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2025-02-21kdb: Do not assume write() callback availableJohn Ogness
commit 6d3e0d8cc63221dec670d0ee92ac57961581e975 upstream. It is allowed for consoles to not provide a write() callback. For example ttynull does this. Check if a write() callback is available before using it. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230717194607.145135-2-john.ogness@linutronix.de Cc: Brian Norris <briannorris@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-21clocksource: Use migrate_disable() to avoid calling get_random_u32() in ↵Waiman Long
atomic context [ Upstream commit 6bb05a33337b2c842373857b63de5c9bf1ae2a09 ] The following bug report happened with a PREEMPT_RT kernel: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2012, name: kwatchdog preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 get_random_u32+0x4f/0x110 clocksource_verify_choose_cpus+0xab/0x1a0 clocksource_verify_percpu.part.0+0x6b/0x330 clocksource_watchdog_kthread+0x193/0x1a0 It is due to the fact that clocksource_verify_choose_cpus() is invoked with preemption disabled. This function invokes get_random_u32() to obtain random numbers for choosing CPUs. The batched_entropy_32 local lock and/or the base_crng.lock spinlock in driver/char/random.c will be acquired during the call. In PREEMPT_RT kernel, they are both sleeping locks and so cannot be acquired in atomic context. Fix this problem by using migrate_disable() to allow smp_processor_id() to be reliably used without introducing atomic context. preempt_disable() is then called after clocksource_verify_choose_cpus() but before the clocksource measurement is being run to avoid introducing unexpected latency. Fixes: 7560c02bdffb ("clocksource: Check per-CPU clock synchronization when marked unstable") Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/all/20250131173323.891943-2-longman@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21clocksource: Use pr_info() for "Checking clocksource synchronization" messageWaiman Long
[ Upstream commit 1f566840a82982141f94086061927a90e79440e5 ] The "Checking clocksource synchronization" message is normally printed when clocksource_verify_percpu() is called for a given clocksource if both the CLOCK_SOURCE_UNSTABLE and CLOCK_SOURCE_VERIFY_PERCPU flags are set. It is an informational message and so pr_info() is the correct choice. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: John Stultz <jstultz@google.com> Link: https://lore.kernel.org/all/20250125015442.3740588-1-longman@redhat.com Stable-dep-of: 6bb05a33337b ("clocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21cgroup: fix race between fork and cgroup.killShakeel Butt
commit b69bb476dee99d564d65d418e9a20acca6f32c3f upstream. Tejun reported the following race between fork() and cgroup.kill at [1]. Tejun: I was looking at cgroup.kill implementation and wondering whether there could be a race window. So, __cgroup_kill() does the following: k1. Set CGRP_KILL. k2. Iterate tasks and deliver SIGKILL. k3. Clear CGRP_KILL. The copy_process() does the following: c1. Copy a bunch of stuff. c2. Grab siglock. c3. Check fatal_signal_pending(). c4. Commit to forking. c5. Release siglock. c6. Call cgroup_post_fork() which puts the task on the css_set and tests CGRP_KILL. The intention seems to be that either a forking task gets SIGKILL and terminates on c3 or it sees CGRP_KILL on c6 and kills the child. However, I don't see what guarantees that k3 can't happen before c6. ie. After a forking task passes c5, k2 can take place and then before the forking task reaches c6, k3 can happen. Then, nobody would send SIGKILL to the child. What am I missing? This is indeed a race. One way to fix this race is by taking cgroup_threadgroup_rwsem in write mode in __cgroup_kill() as the fork() side takes cgroup_threadgroup_rwsem in read mode from cgroup_can_fork() to cgroup_post_fork(). However that would be heavy handed as this adds one more potential stall scenario for cgroup.kill which is usually called under extreme situation like memory pressure. To fix this race, let's maintain a sequence number per cgroup which gets incremented on __cgroup_kill() call. On the fork() side, the cgroup_can_fork() will cache the sequence number locally and recheck it against the cgroup's sequence number at cgroup_post_fork() site. If the sequence numbers mismatch, it means __cgroup_kill() can been called and we should send SIGKILL to the newly created task. Reported-by: Tejun Heo <tj@kernel.org> Closes: https://lore.kernel.org/all/Z5QHE2Qn-QZ6M-KW@slm.duckdns.org/ [1] Fixes: 661ee6280931 ("cgroup: introduce cgroup.kill") Cc: stable@vger.kernel.org # v5.14+ Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-21cgroup: Remove steal time from usage_usecMuhammad Adeel
[ Upstream commit db5fd3cf8bf41b84b577b8ad5234ea95f327c9be ] The CPU usage time is the time when user, system or both are using the CPU. Steal time is the time when CPU is waiting to be run by the Hypervisor. It should not be added to the CPU usage time, hence removing it from the usage_usec entry. Fixes: 936f2a70f2077 ("cgroup: add cpu.stat file to root cgroup") Acked-by: Axel Busch <axel.busch@ibm.com> Acked-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Muhammad Adeel <muhammad.adeel@ibm.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAXKuan-Wei Chiu
[ Upstream commit 3d6f83df8ff2d5de84b50377e4f0d45e25311c7a ] Shifting 1 << 31 on a 32-bit int causes signed integer overflow, which leads to undefined behavior. To prevent this, cast 1 to u32 before performing the shift, ensuring well-defined behavior. This change explicitly avoids any potential overflow by ensuring that the shift occurs on an unsigned 32-bit integer. Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240928113608.1438087-1-visitorckw@gmail.com Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21sched: Don't try to catch up excess steal time.Suleiman Souhlal
[ Upstream commit 108ad0999085df2366dd9ef437573955cb3f5586 ] When steal time exceeds the measured delta when updating clock_task, we currently try to catch up the excess in future updates. However, this results in inaccurate run times for the future things using clock_task, in some situations, as they end up getting additional steal time that did not actually happen. This is because there is a window between reading the elapsed time in update_rq_clock() and sampling the steal time in update_rq_clock_task(). If the VCPU gets preempted between those two points, any additional steal time is accounted to the outgoing task even though the calculated delta did not actually contain any of that "stolen" time. When this race happens, we can end up with steal time that exceeds the calculated delta, and the previous code would try to catch up that excess steal time in future clock updates, which is given to the next, incoming task, even though it did not actually have any time stolen. This behavior is particularly bad when steal time can be very long, which we've seen when trying to extend steal time to contain the duration that the host was suspended [0]. When this happens, clock_task stays frozen, during which the running task stays running for the whole duration, since its run time doesn't increase. However the race can happen even under normal operation. Ideally we would read the elapsed cpu time and the steal time atomically, to prevent this race from happening in the first place, but doing so is non-trivial. Since the time between those two points isn't otherwise accounted anywhere, neither to the outgoing task nor the incoming task (because the "end of outgoing task" and "start of incoming task" timestamps are the same), I would argue that the right thing to do is to simply drop any excess steal time, in order to prevent these issues. [0] https://lore.kernel.org/kvm/20240820043543.837914-1-suleiman@google.com/ Signed-off-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241118043745.1857272-1-suleiman@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21PM: hibernate: Add error handling for syscore_suspend()Wentao Liang
[ Upstream commit e20a70c572539a486dbd91b225fa6a194a5e2122 ] In hibernation_platform_enter(), the code did not check the return value of syscore_suspend(), potentially leading to a situation where syscore_resume() would be called even if syscore_suspend() failed. This could cause unpredictable behavior or system instability. Modify the code sequence in question to properly handle errors returned by syscore_suspend(). If an error occurs in the suspend path, the code now jumps to label 'Enable_irqs' skipping the syscore_resume() call and only enabling interrupts after setting the system state to SYSTEM_RUNNING. Fixes: 40dc166cb5dd ("PM / Core: Introduce struct syscore_ops for core subsystems PM") Signed-off-by: Wentao Liang <vulab@iscas.ac.cn> Link: https://patch.msgid.link/20250119143205.2103-1-vulab@iscas.ac.cn [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21padata: avoid UAF for reorder_workChen Ridong
[ Upstream commit dd7d37ccf6b11f3d95e797ebe4e9e886d0332600 ] Although the previous patch can avoid ps and ps UAF for _do_serial, it can not avoid potential UAF issue for reorder_work. This issue can happen just as below: crypto_request crypto_request crypto_del_alg padata_do_serial ... padata_reorder // processes all remaining // requests then breaks while (1) { if (!padata) break; ... } padata_do_serial // new request added list_add // sees the new request queue_work(reorder_work) padata_reorder queue_work_on(squeue->work) ... <kworker context> padata_serial_worker // completes new request, // no more outstanding // requests crypto_del_alg // free pd <kworker context> invoke_padata_reorder // UAF of pd To avoid UAF for 'reorder_work', get 'pd' ref before put 'reorder_work' into the 'serial_wq' and put 'pd' ref until the 'serial_wq' finish. Fixes: bbefa1dd6a6d ("crypto: pcrypt - Avoid deadlock by using per-instance padata queues") Signed-off-by: Chen Ridong <chenridong@huawei.com> Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21padata: add pd get/put refcnt helperChen Ridong
[ Upstream commit ae154202cc6a189b035359f3c4e143d5c24d5352 ] Add helpers for pd to get/put refcnt to make code consice. Signed-off-by: Chen Ridong <chenridong@huawei.com> Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Stable-dep-of: dd7d37ccf6b1 ("padata: avoid UAF for reorder_work") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21padata: fix UAF in padata_reorderChen Ridong
[ Upstream commit e01780ea4661172734118d2a5f41bc9720765668 ] A bug was found when run ltp test: BUG: KASAN: slab-use-after-free in padata_find_next+0x29/0x1a0 Read of size 4 at addr ffff88bbfe003524 by task kworker/u113:2/3039206 CPU: 0 PID: 3039206 Comm: kworker/u113:2 Kdump: loaded Not tainted 6.6.0+ Workqueue: pdecrypt_parallel padata_parallel_worker Call Trace: <TASK> dump_stack_lvl+0x32/0x50 print_address_description.constprop.0+0x6b/0x3d0 print_report+0xdd/0x2c0 kasan_report+0xa5/0xd0 padata_find_next+0x29/0x1a0 padata_reorder+0x131/0x220 padata_parallel_worker+0x3d/0xc0 process_one_work+0x2ec/0x5a0 If 'mdelay(10)' is added before calling 'padata_find_next' in the 'padata_reorder' function, this issue could be reproduced easily with ltp test (pcrypt_aead01). This can be explained as bellow: pcrypt_aead_encrypt ... padata_do_parallel refcount_inc(&pd->refcnt); // add refcnt ... padata_do_serial padata_reorder // pd while (1) { padata_find_next(pd, true); // using pd queue_work_on ... padata_serial_worker crypto_del_alg padata_put_pd_cnt // sub refcnt padata_free_shell padata_put_pd(ps->pd); // pd is freed // loop again, but pd is freed // call padata_find_next, UAF } In the padata_reorder function, when it loops in 'while', if the alg is deleted, the refcnt may be decreased to 0 before entering 'padata_find_next', which leads to UAF. As mentioned in [1], do_serial is supposed to be called with BHs disabled and always happen under RCU protection, to address this issue, add synchronize_rcu() in 'padata_free_shell' wait for all _do_serial calls to finish. [1] https://lore.kernel.org/all/20221028160401.cccypv4euxikusiq@parnassus.localdomain/ [2] https://lore.kernel.org/linux-kernel/jfjz5d7zwbytztackem7ibzalm5lnxldi2eofeiczqmqs2m7o6@fq426cwnjtkm/ Fixes: b128a3040935 ("padata: allocate workqueue internally") Signed-off-by: Chen Ridong <chenridong@huawei.com> Signed-off-by: Qu Zicheng <quzicheng@huawei.com> Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21bpf: Send signals asynchronously if !preemptiblePuranjay Mohan
[ Upstream commit 87c544108b612512b254c8f79aa5c0a8546e2cc4 ] BPF programs can execute in all kinds of contexts and when a program running in a non-preemptible context uses the bpf_send_signal() kfunc, it will cause issues because this kfunc can sleep. Change `irqs_disabled()` to `!preemptible()`. Reported-by: syzbot+97da3d7e0112d59971de@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67486b09.050a0220.253251.0084.GAE@google.com/ Fixes: 1bc7896e9ef4 ("bpf: Fix deadlock with rq_lock in bpf_send_signal()") Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20250115103647.38487-1-puranjay@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21padata: fix sysfs store callback checkThomas Weißschuh
[ Upstream commit 9ff6e943bce67d125781fe4780a5d6f072dc44c0 ] padata_sysfs_store() was copied from padata_sysfs_show() but this check was not adapted. Today there is no attribute which can fail this check, but if there is one it may as well be correct. Fixes: 5e017dc3f8bc ("padata: Added sysfs primitives to padata subsystem") Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21cpufreq: schedutil: Fix superfluous updates caused by need_freq_updateSultan Alsawaf (unemployed)
[ Upstream commit 8e461a1cb43d69d2fc8a97e61916dce571e6bb31 ] A redundant frequency update is only truly needed when there is a policy limits change with a driver that specifies CPUFREQ_NEED_UPDATE_LIMITS. In spite of that, drivers specifying CPUFREQ_NEED_UPDATE_LIMITS receive a frequency update _all the time_, not just for a policy limits change, because need_freq_update is never cleared. Furthermore, ignore_dl_rate_limit()'s usage of need_freq_update also leads to a redundant frequency update, regardless of whether or not the driver specifies CPUFREQ_NEED_UPDATE_LIMITS, when the next chosen frequency is the same as the current one. Fix the superfluous updates by only honoring CPUFREQ_NEED_UPDATE_LIMITS when there's a policy limits change, and clearing need_freq_update when a requisite redundant update occurs. This is neatly achieved by moving up the CPUFREQ_NEED_UPDATE_LIMITS test and instead setting need_freq_update to false in sugov_update_next_freq(). Fixes: 600f5badb78c ("cpufreq: schedutil: Don't skip freq update when limits change") Signed-off-by: Sultan Alsawaf (unemployed) <sultan@kerneltoast.com> Reviewed-by: Christian Loehle <christian.loehle@arm.com> Link: https://patch.msgid.link/20241212015734.41241-2-sultan@kerneltoast.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21genirq: Make handle_enforce_irqctx() unconditionally availableThomas Gleixner
[ Upstream commit 8d187a77f04c14fb459a5301d69f733a5a1396bc ] Commit 1b57d91b969c ("irqchip/gic-v2, v3: Prevent SW resends entirely") sett the flag which enforces interrupt handling in interrupt context and prevents software base resends for ARM GIC v2/v3. But it missed that the helper function which checks the flag was hidden behind CONFIG_GENERIC_PENDING_IRQ, which is not set by ARM[64]. Make the helper unconditionally available so that the enforcement actually works. Fixes: 1b57d91b969c ("irqchip/gic-v2, v3: Prevent SW resends entirely") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241210101811.497716609@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21sched/fair: Fix value reported by hot tasks pulled in /proc/schedstatPeter Zijlstra
[ Upstream commit a430d99e349026d53e2557b7b22bd2ebd61fe12a ] In /proc/schedstat, lb_hot_gained reports the number hot tasks pulled during load balance. This value is incremented in can_migrate_task() if the task is migratable and hot. After incrementing the value, load balancer can still decide not to migrate this task leading to wrong accounting. Fix this by incrementing stats when hot tasks are detached. This issue only exists in detach_tasks() where we can decide to not migrate hot task even if it is migratable. However, in detach_one_task(), we migrate it unconditionally. [Swapnil: Handled the case where nr_failed_migrations_hot was not accounted properly and wrote commit log] Fixes: d31980846f96 ("sched: Move up affinity check to mitigate useless redoing overhead") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reported-by: "Gautham R. Shenoy" <gautham.shenoy@amd.com> Not-yet-signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241220063224.17767-2-swapnil.sapkal@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21sched/psi: Use task->psi_flags to clear in CPU migrationChengming Zhou
[ Upstream commit 52b33d87b9197c51e8ffdc61873739d90dd0a16f ] The commit d583d360a620 ("psi: Fix psi state corruption when schedule() races with cgroup move") fixed a race problem by making cgroup_move_task() use task->psi_flags instead of looking at the scheduler state. We can extend task->psi_flags usage to CPU migration, which should be a minor optimization for performance and code simplicity. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20220926081931.45420-1-zhouchengming@bytedance.com Stable-dep-of: a430d99e3490 ("sched/fair: Fix value reported by hot tasks pulled in /proc/schedstat") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-01softirq: Allow raising SCHED_SOFTIRQ from SMP-call-function on RT kernelK Prateek Nayak
commit 6675ce20046d149e1e1ffe7e9577947dee17aad5 upstream. do_softirq_post_smp_call_flush() on PREEMPT_RT kernels carries a WARN_ON_ONCE() for any SOFTIRQ being raised from an SMP-call-function. Since do_softirq_post_smp_call_flush() is called with preempt disabled, raising a SOFTIRQ during flush_smp_call_function_queue() can lead to longer preempt disabled sections. Since commit b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()") IPIs to an idle CPU in TIF_POLLING_NRFLAG mode can be optimized out by instead setting TIF_NEED_RESCHED bit in idle task's thread_info and relying on the flush_smp_call_function_queue() in the idle-exit path to run the SMP-call-function. To trigger an idle load balancing, the scheduler queues nohz_csd_function() responsible for triggering an idle load balancing on a target nohz idle CPU and sends an IPI. Only now, this IPI is optimized out and the SMP-call-function is executed from flush_smp_call_function_queue() in do_idle() which can raise a SCHED_SOFTIRQ to trigger the balancing. So far, this went undetected since, the need_resched() check in nohz_csd_function() would make it bail out of idle load balancing early as the idle thread does not clear TIF_POLLING_NRFLAG before calling flush_smp_call_function_queue(). The need_resched() check was added with the intent to catch a new task wakeup, however, it has recently discovered to be unnecessary and will be removed in the subsequent commit after which nohz_csd_function() can raise a SCHED_SOFTIRQ from flush_smp_call_function_queue() to trigger an idle load balance on an idle target in TIF_POLLING_NRFLAG mode. nohz_csd_function() bails out early if "idle_cpu()" check for the target CPU, and does not lock the target CPU's rq until the very end, once it has found tasks to run on the CPU and will not inhibit the wakeup of, or running of a newly woken up higher priority task. Account for this and prevent a WARN_ON_ONCE() when SCHED_SOFTIRQ is raised from flush_smp_call_function_queue(). Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241119054432.6405-2-kprateek.nayak@amd.com Tested-by: Felix Moessbauer <felix.moessbauer@siemens.com> Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-23hrtimers: Handle CPU state correctly on hotplugKoichiro Den
commit 2f8dea1692eef2b7ba6a256246ed82c365fdc686 upstream. Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to CPUHP_ONLINE: Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set to 1 throughout. However, during a CPU unplug operation, the tick and the clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online state, for instance CFS incorrectly assumes that the hrtick is already active, and the chance of the clockevent device to transition to oneshot mode is also lost forever for the CPU, unless it goes back to a lower state than CPUHP_HRTIMERS_PREPARE once. This round-trip reveals another issue; cpu_base.online is not set to 1 after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer(). Aside of that, the bulk of the per CPU state is not reset either, which means there are dangling pointers in the worst case. Address this by adding a corresponding startup() callback, which resets the stale per CPU state and sets the online flag. [ tglx: Make the new callback unconditionally available, remove the online modification in the prepare() callback and clear the remaining state in the starting callback instead of the prepare callback ] Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier") Signed-off-by: Koichiro Den <koichiro.den@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20241220134421.3809834-1-koichiro.den@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-23kheaders: Ignore silly-rename filesDavid Howells
[ Upstream commit 973b710b8821c3401ad7a25360c89e94b26884ac ] Tell tar to ignore silly-rename files (".__afs*" and ".nfs*") when building the header archive. These occur when a file that is open is unlinked locally, but hasn't yet been closed. Such files are visible to the user via the getdents() syscall and so programs may want to do things with them. During the kernel build, such files may be made during the processing of header files and the cleanup may get deferred by fput() which may result in tar seeing these files when it reads the directory, but they may have disappeared by the time it tries to open them, causing tar to fail with an error. Further, we don't want to include them in the tarball if they still exist. With CONFIG_HEADERS_INSTALL=y, something like the following may be seen: find: './kernel/.tmp_cpio_dir/include/dt-bindings/reset/.__afs2080': No such file or directory tar: ./include/linux/greybus/.__afs3C95: File removed before we read it The find warning doesn't seem to cause a problem. Fix this by telling tar when called from in gen_kheaders.sh to exclude such files. This only affects afs and nfs; cifs uses the Windows Hidden attribute to prevent the file from being seen. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241213135013.2964079-2-dhowells@redhat.com cc: Masahiro Yamada <masahiroy@kernel.org> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-nfs@vger.kernel.org cc: linux-kernel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-17bpf: Fix overloading of MEM_UNINIT's meaningDaniel Borkmann
commit 8ea607330a39184f51737c6ae706db7fdca7628e upstream. Lonial reported an issue in the BPF verifier where check_mem_size_reg() has the following code: if (!tnum_is_const(reg->var_off)) /* For unprivileged variable accesses, disable raw * mode so that the program is required to * initialize all the memory that the helper could * just partially fill up. */ meta = NULL; This means that writes are not checked when the register containing the size of the passed buffer has not a fixed size. Through this bug, a BPF program can write to a map which is marked as read-only, for example, .rodata global maps. The problem is that MEM_UNINIT's initial meaning that "the passed buffer to the BPF helper does not need to be initialized" which was added back in commit 435faee1aae9 ("bpf, verifier: add ARG_PTR_TO_RAW_STACK type") got overloaded over time with "the passed buffer is being written to". The problem however is that checks such as the above which were added later via 06c1c049721a ("bpf: allow helpers access to variable memory") set meta to NULL in order force the user to always initialize the passed buffer to the helper. Due to the current double meaning of MEM_UNINIT, this bypasses verifier write checks to the memory (not boundary checks though) and only assumes the latter memory is read instead. Fix this by reverting MEM_UNINIT back to its original meaning, and having MEM_WRITE as an annotation to BPF helpers in order to then trigger the BPF verifier checks for writing to memory. Some notes: check_arg_pair_ok() ensures that for ARG_CONST_SIZE{,_OR_ZERO} we can access fn->arg_type[arg - 1] since it must contain a preceding ARG_PTR_TO_MEM. For check_mem_reg() the meta argument can be removed altogether since we do check both BPF_READ and BPF_WRITE. Same for the equivalent check_kfunc_mem_size_reg(). Fixes: 7b3552d3f9f6 ("bpf: Reject writes for PTR_TO_MAP_KEY in check_helper_mem_access") Fixes: 97e6d7dab1ca ("bpf: Check PTR_TO_MEM | MEM_RDONLY in check_helper_mem_access") Fixes: 15baa55ff5b0 ("bpf/verifier: allow all functions to read user provided context") Reported-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241021152809.33343-2-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: BRUNO VERNAY <bruno.vernay@se.com> Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17bpf: Add MEM_WRITE attributeDaniel Borkmann
commit 6fad274f06f038c29660aa53fbad14241c9fd976 upstream. Add a MEM_WRITE attribute for BPF helper functions which can be used in bpf_func_proto to annotate an argument type in order to let the verifier know that the helper writes into the memory passed as an argument. In the past MEM_UNINIT has been (ab)used for this function, but the latter merely tells the verifier that the passed memory can be uninitialized. There have been bugs with overloading the latter but aside from that there are also cases where the passed memory is read + written which currently cannot be expressed, see also 4b3786a6c539 ("bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error"). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241021152809.33343-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: BRUNO VERNAY <bruno.vernay@se.com> Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com> Stable-dep-of: 8ea607330a39 ("bpf: Fix overloading of MEM_UNINIT's meaning") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-09kcov: mark in_softirq_really() as __always_inlineArnd Bergmann
commit cb0ca08b326aa03f87fe94bb91872ce8d2ef1ed8 upstream. If gcc decides not to inline in_softirq_really(), objtool warns about a function call with UACCESS enabled: kernel/kcov.o: warning: objtool: __sanitizer_cov_trace_pc+0x1e: call to in_softirq_really() with UACCESS enabled kernel/kcov.o: warning: objtool: check_kcov_mode+0x11: call to in_softirq_really() with UACCESS enabled Mark this as __always_inline to avoid the problem. Link: https://lkml.kernel.org/r/20241217071814.2261620-1-arnd@kernel.org Fixes: 7d4df2dad312 ("kcov: properly check for softirq context") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Marco Elver <elver@google.com> Cc: Aleksandr Nogikh <nogikh@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-09bpf: fix potential error returnAnton Protopopov
[ Upstream commit c4441ca86afe4814039ee1b32c39d833c1a16bbc ] The bpf_remove_insns() function returns WARN_ON_ONCE(error), where error is a result of bpf_adj_branches(), and thus should be always 0 However, if for any reason it is not 0, then it will be converted to boolean by WARN_ON_ONCE and returned to user space as 1, not an actual error value. Fix this by returning the original err after the WARN check. Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241210114245.836164-1-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-09tracing: Have process_string() also allow arraysSteven Rostedt
commit afc6717628f959941d7b33728570568b4af1c4b8 upstream. In order to catch a common bug where a TRACE_EVENT() TP_fast_assign() assigns an address of an allocated string to the ring buffer and then references it in TP_printk(), which can be executed hours later when the string is free, the function test_event_printk() runs on all events as they are registered to make sure there's no unwanted dereferencing. It calls process_string() to handle cases in TP_printk() format that has "%s". It returns whether or not the string is safe. But it can have some false positives. For instance, xe_bo_move() has: TP_printk("move_lacks_source:%s, migrate object %p [size %zu] from %s to %s device_id:%s", __entry->move_lacks_source ? "yes" : "no", __entry->bo, __entry->size, xe_mem_type_to_name[__entry->old_placement], xe_mem_type_to_name[__entry->new_placement], __get_str(device_id)) Where the "%s" references into xe_mem_type_to_name[]. This is an array of pointers that should be safe for the event to access. Instead of flagging this as a bad reference, if a reference points to an array, where the record field is the index, consider it safe. Link: https://lore.kernel.org/all/9dee19b6185d325d0e6fa5f7cbba81d007d99166.camel@sapience.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241231000646.324fb5f7@gandalf.local.home Fixes: 65a25d9f7ac02 ("tracing: Add "%s" check in test_event_printk()") Reported-by: Genes Lists <lists@sapience.com> Tested-by: Gene C <arch@sapience.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-02Revert "rcu-tasks: Fix access non-existent percpu rtpcp variable in ↵Greg Kroah-Hartman
rcu_tasks_need_gpcb()" This reverts commit 224fd631c41b81697aa622d38615bfbf446b91cf which is commit fd70e9f1d85f5323096ad313ba73f5fe3d15ea41 upstream. It is reported to cause problems in testing, so revert it for now. Link: https://lore.kernel.org/r/20241216-comic-handling-3bcf108cc465@wendy Reported-by: Conor Dooley <conor.dooley@microchip.com> CC: Zhixu Liu <zhixu.liu@gmail.com> Cc: Zqiang <qiang.zhang1211@gmail.com> Cc: Neeraj Upadhyay <neeraj.upadhyay@kernel.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Xiangyu Chen <xiangyu.chen@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-02tracing: Prevent bad count for tracing_cpumask_writeLizhi Xu
commit 98feccbf32cfdde8c722bc4587aaa60ee5ac33f0 upstream. If a large count is provided, it will trigger a warning in bitmap_parse_user. Also check zero for it. Cc: stable@vger.kernel.org Fixes: 9e01c1b74c953 ("cpumask: convert kernel trace functions") Link: https://lore.kernel.org/20241216073238.2573704-1-lizhi.xu@windriver.com Reported-by: syzbot+0aecfd34fb878546f3fd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0aecfd34fb878546f3fd Tested-by: syzbot+0aecfd34fb878546f3fd@syzkaller.appspotmail.com Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-02bpf: Check validity of link->type in bpf_link_show_fdinfo()Hou Tao
commit 8421d4c8762bd022cb491f2f0f7019ef51b4f0a7 upstream. If a newly-added link type doesn't invoke BPF_LINK_TYPE(), accessing bpf_link_type_strs[link->type] may result in an out-of-bounds access. To spot such missed invocations early in the future, checking the validity of link->type in bpf_link_show_fdinfo() and emitting a warning when such invocations are missed. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241024013558.1135167-3-houtao@huaweicloud.com [ shung-hsi.yu: break up existing seq_printf() call since commit 68b04864ca42 ("bpf: Create links for BPF struct_ops maps.") is not present ] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-02tracing/kprobe: Make trace_kprobe's module callback called after jump_label ↵Masami Hiramatsu (Google)
update [ Upstream commit d685d55dfc86b1a4bdcec77c3c1f8a83f181264e ] Make sure the trace_kprobe's module notifer callback function is called after jump_label's callback is called. Since the trace_kprobe's callback eventually checks jump_label address during registering new kprobe on the loading module, jump_label must be updated before this registration happens. Link: https://lore.kernel.org/all/173387585556.995044.3157941002975446119.stgit@devnote2/ Fixes: 614243181050 ("tracing/kprobes: Support module init function probing") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-27tracing: Add "%s" check in test_event_printk()Steven Rostedt
commit 65a25d9f7ac02e0cf361356e834d1c71d36acca9 upstream. The test_event_printk() code makes sure that when a trace event is registered, any dereferenced pointers in from the event's TP_printk() are pointing to content in the ring buffer. But currently it does not handle "%s", as there's cases where the string pointer saved in the ring buffer points to a static string in the kernel that will never be freed. As that is a valid case, the pointer needs to be checked at runtime. Currently the runtime check is done via trace_check_vprintf(), but to not have to replicate everything in vsnprintf() it does some logic with the va_list that may not be reliable across architectures. In order to get rid of that logic, more work in the test_event_printk() needs to be done. Some of the strings can be validated at this time when it is obvious the string is valid because the string will be saved in the ring buffer content. Do all the validation of strings in the ring buffer at boot in test_event_printk(), and make sure that the field of the strings that point into the kernel are accessible. This will allow adding checks at runtime that will validate the fields themselves and not rely on paring the TP_printk() format at runtime. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/20241217024720.685917008@goodmis.org Fixes: 5013f454a352c ("tracing: Add check of trace event print fmts for dereferencing pointers") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-27tracing: Add missing helper functions in event pointer dereference checkSteven Rostedt
commit 917110481f6bc1c96b1e54b62bb114137fbc6d17 upstream. The process_pointer() helper function looks to see if various trace event macros are used. These macros are for storing data in the event. This makes it safe to dereference as the dereference will then point into the event on the ring buffer where the content of the data stays with the event itself. A few helper functions were missing. Those were: __get_rel_dynamic_array() __get_dynamic_array_len() __get_rel_dynamic_array_len() __get_rel_sockaddr() Also add a helper function find_print_string() to not need to use a middle man variable to test if the string exists. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/20241217024720.521836792@goodmis.org Fixes: 5013f454a352c ("tracing: Add check of trace event print fmts for dereferencing pointers") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-27tracing: Fix test_event_printk() to process entire print argumentSteven Rostedt
commit a6629626c584200daf495cc9a740048b455addcd upstream. The test_event_printk() analyzes print formats of trace events looking for cases where it may dereference a pointer that is not in the ring buffer which can possibly be a bug when the trace event is read from the ring buffer and the content of that pointer no longer exists. The function needs to accurately go from one print format argument to the next. It handles quotes and parenthesis that may be included in an argument. When it finds the start of the next argument, it uses a simple "c = strstr(fmt + i, ',')" to find the end of that argument! In order to include "%s" dereferencing, it needs to process the entire content of the print format argument and not just the content of the first ',' it finds. As there may be content like: ({ const char *saved_ptr = trace_seq_buffer_ptr(p); static const char *access_str[] = { "---", "--x", "w--", "w-x", "-u-", "-ux", "wu-", "wux" }; union kvm_mmu_page_role role; role.word = REC->role; trace_seq_printf(p, "sp gen %u gfn %llx l%u %u-byte q%u%s %s%s" " %snxe %sad root %u %s%c", REC->mmu_valid_gen, REC->gfn, role.level, role.has_4_byte_gpte ? 4 : 8, role.quadrant, role.direct ? " direct" : "", access_str[role.access], role.invalid ? " invalid" : "", role.efer_nx ? "" : "!", role.ad_disabled ? "!" : "", REC->root_count, REC->unsync ? "unsync" : "sync", 0); saved_ptr; }) Which is an example of a full argument of an existing event. As the code already handles finding the next print format argument, process the argument at the end of it and not the start of it. This way it has both the start of the argument as well as the end of it. Add a helper function "process_pointer()" that will do the processing during the loop as well as at the end. It also makes the code cleaner and easier to read. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/20241217024720.362271189@goodmis.org Fixes: 5013f454a352c ("tracing: Add check of trace event print fmts for dereferencing pointers") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-19x86/static-call: provide a way to do very early static-call updatesJuergen Gross
commit 0ef8047b737d7480a5d4c46d956e97c190f13050 upstream. Add static_call_update_early() for updating static-call targets in very early boot. This will be needed for support of Xen guest type specific hypercall functions. This is part of XSA-466 / CVE-2024-53241. Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com> Co-developed-by: Peter Zijlstra <peterz@infradead.org> Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-19tracing/kprobes: Skip symbol counting logic for module symbols in ↵Nikolay Kuratov
create_local_trace_kprobe() commit b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols") avoids checking number_of_same_symbols() for module symbol in __trace_kprobe_create(), but create_local_trace_kprobe() should avoid this check too. Doing this check leads to ENOENT for module_name:symbol_name constructions passed over perf_event_open. No bug in newer kernels as it was fixed more generally by commit 9d8616034f16 ("tracing/kprobes: Add symbol counting check when module loads") Link: https://lore.kernel.org/linux-trace-kernel/20240705161030.b3ddb33a8167013b9b1da202@kernel.org Fixes: b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols") Signed-off-by: Nikolay Kuratov <kniv@yandex-team.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-19bpf: sync_linked_regs() must preserve subreg_defEduard Zingerman
commit e9bd9c498cb0f5843996dbe5cbce7a1836a83c70 upstream. Range propagation must not affect subreg_def marks, otherwise the following example is rewritten by verifier incorrectly when BPF_F_TEST_RND_HI32 flag is set: 0: call bpf_ktime_get_ns call bpf_ktime_get_ns 1: r0 &= 0x7fffffff after verifier r0 &= 0x7fffffff 2: w1 = w0 rewrites w1 = w0 3: if w0 < 10 goto +0 --------------> r11 = 0x2f5674a6 (r) 4: r1 >>= 32 r11 <<= 32 (r) 5: r0 = r1 r1 |= r11 (r) 6: exit; if w0 < 0xa goto pc+0 r1 >>= 32 r0 = r1 exit (or zero extension of w1 at (2) is missing for architectures that require zero extension for upper register half). The following happens w/o this patch: - r0 is marked as not a subreg at (0); - w1 is marked as subreg at (2); - w1 subreg_def is overridden at (3) by copy_register_state(); - w1 is read at (5) but mark_insn_zext() does not mark (2) for zero extension, because w1 subreg_def is not set; - because of BPF_F_TEST_RND_HI32 flag verifier inserts random value for hi32 bits of (2) (marked (r)); - this random value is read at (5). Fixes: 75748837b7e5 ("bpf: Propagate scalar ranges through register assignments.") Reported-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Closes: https://lore.kernel.org/bpf/7e2aa30a62d740db182c170fdd8f81c596df280d.camel@gmail.com Link: https://lore.kernel.org/bpf/20240924210844.1758441-1-eddyz87@gmail.com [ shung-hsi.yu: sync_linked_regs() was called find_equal_scalars() before commit 4bf79f9be434 ("bpf: Track equal scalars history on per-instruction level"), and modification is done because there is only a single call to copy_register_state() before commit 98d7ca374ba4 ("bpf: Track delta between "linked" registers."). ] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-19bpf,perf: Fix invalid prog_array access in perf_event_detach_bpf_progJiri Olsa
commit 978c4486cca5c7b9253d3ab98a88c8e769cb9bbd upstream. Syzbot reported [1] crash that happens for following tracing scenario: - create tracepoint perf event with attr.inherit=1, attach it to the process and set bpf program to it - attached process forks -> chid creates inherited event the new child event shares the parent's bpf program and tp_event (hence prog_array) which is global for tracepoint - exit both process and its child -> release both events - first perf_event_detach_bpf_prog call will release tp_event->prog_array and second perf_event_detach_bpf_prog will crash, because tp_event->prog_array is NULL The fix makes sure the perf_event_detach_bpf_prog checks prog_array is valid before it tries to remove the bpf program from it. [1] https://lore.kernel.org/bpf/Z1MR6dCIKajNS6nU@krava/T/#m91dbf0688221ec7a7fc95e896a7ef9ff93b0b8ad Fixes: 0ee288e69d03 ("bpf,perf: Fix perf_event_detach_bpf_prog error handling") Reported-by: syzbot+2e0d2840414ce817aaac@syzkaller.appspotmail.com Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241208142507.1207698-1-jolsa@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-19bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavorsJann Horn
commit ef1b808e3b7c98612feceedf985c2fbbeb28f956 upstream. Uprobes always use bpf_prog_run_array_uprobe() under tasks-trace-RCU protection. But it is possible to attach a non-sleepable BPF program to a uprobe, and non-sleepable BPF programs are freed via normal RCU (see __bpf_prog_put_noref()). This leads to UAF of the bpf_prog because a normal RCU grace period does not imply a tasks-trace-RCU grace period. Fix it by explicitly waiting for a tasks-trace-RCU grace period after removing the attachment of a bpf_prog to a perf_event. Fixes: 8c7dcb84e3b7 ("bpf: implement sleepable uprobes by chaining gps") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/bpf/20241210-bpf-fix-actual-uprobe-uaf-v1-1-19439849dd44@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14bpf: Fix helper writes to read-only mapsDaniel Borkmann
commit 32556ce93bc45c730829083cb60f95a2728ea48b upstream. Lonial found an issue that despite user- and BPF-side frozen BPF map (like in case of .rodata), it was still possible to write into it from a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT} as arguments. In check_func_arg() when the argument is as mentioned, the meta->raw_mode is never set. Later, check_helper_mem_access(), under the case of PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the subsequent call to check_map_access_type() and given the BPF map is read-only it succeeds. The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT when results are written into them as opposed to read out of them. The latter indicates that it's okay to pass a pointer to uninitialized memory as the memory is written to anyway. However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM just with additional alignment requirement. So it is better to just get rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the fixed size memory types. For this, add MEM_ALIGNED to additionally ensure alignment given these helpers write directly into the args via *<ptr> = val. The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>). MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated argument types, since in !MEM_FIXED_SIZE cases the verifier does not know the buffer size a priori and therefore cannot blindly write *<ptr> = val. Fixes: 57c3bb725a3d ("bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types") Reported-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Link: https://lore.kernel.org/r/20240913191754.13290-3-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> [ Resolve merge conflict in include/linux/bpf.h and merge conflict in kernel/bpf/verifier.c.] Signed-off-by: Bin Lan <bin.lan.cn@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14tracing/eprobe: Fix to release eprobe when failed to add dyn_eventMasami Hiramatsu (Google)
[ Upstream commit 494b332064c0ce2f7392fa92632bc50191c1b517 ] Fix eprobe event to unregister event call and release eprobe when it fails to add dynamic event correctly. Link: https://lore.kernel.org/all/173289886698.73724.1959899350183686006.stgit@devnote2/ Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14sched/core: Prevent wakeup of ksoftirqd during idle load balanceK Prateek Nayak
[ Upstream commit e932c4ab38f072ce5894b2851fea8bc5754bb8e5 ] Scheduler raises a SCHED_SOFTIRQ to trigger a load balancing event on from the IPI handler on the idle CPU. If the SMP function is invoked from an idle CPU via flush_smp_call_function_queue() then the HARD-IRQ flag is not set and raise_softirq_irqoff() needlessly wakes ksoftirqd because soft interrupts are handled before ksoftirqd get on the CPU. Adding a trace_printk() in nohz_csd_func() at the spot of raising SCHED_SOFTIRQ and enabling trace events for sched_switch, sched_wakeup, and softirq_entry (for SCHED_SOFTIRQ vector alone) helps observing the current behavior: <idle>-0 [000] dN.1.: nohz_csd_func: Raising SCHED_SOFTIRQ from nohz_csd_func <idle>-0 [000] dN.4.: sched_wakeup: comm=ksoftirqd/0 pid=16 prio=120 target_cpu=000 <idle>-0 [000] .Ns1.: softirq_entry: vec=7 [action=SCHED] <idle>-0 [000] .Ns1.: softirq_exit: vec=7 [action=SCHED] <idle>-0 [000] d..2.: sched_switch: prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=ksoftirqd/0 next_pid=16 next_prio=120 ksoftirqd/0-16 [000] d..2.: sched_switch: prev_comm=ksoftirqd/0 prev_pid=16 prev_prio=120 prev_state=S ==> next_comm=swapper/0 next_pid=0 next_prio=120 ... Use __raise_softirq_irqoff() to raise the softirq. The SMP function call is always invoked on the requested CPU in an interrupt handler. It is guaranteed that soft interrupts are handled at the end. Following are the observations with the changes when enabling the same set of events: <idle>-0 [000] dN.1.: nohz_csd_func: Raising SCHED_SOFTIRQ for nohz_idle_balance <idle>-0 [000] dN.1.: softirq_raise: vec=7 [action=SCHED] <idle>-0 [000] .Ns1.: softirq_entry: vec=7 [action=SCHED] No unnecessary ksoftirqd wakeups are seen from idle task's context to service the softirq. Fixes: b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()") Closes: https://lore.kernel.org/lkml/fcf823f-195e-6c9a-eac3-25f870cb35ac@inria.fr/ [1] Reported-by: Julia Lawall <julia.lawall@inria.fr> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/r/20241119054432.6405-5-kprateek.nayak@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14sched/fair: Check idle_cpu() before need_resched() to detect ilb CPU turning ↵K Prateek Nayak
busy [ Upstream commit ff47a0acfcce309cf9e175149c75614491953c8f ] Commit b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()") optimizes IPIs to idle CPUs in TIF_POLLING_NRFLAG mode by setting the TIF_NEED_RESCHED flag in idle task's thread info and relying on flush_smp_call_function_queue() in idle exit path to run the call-function. A softirq raised by the call-function is handled shortly after in do_softirq_post_smp_call_flush() but the TIF_NEED_RESCHED flag remains set and is only cleared later when schedule_idle() calls __schedule(). need_resched() check in _nohz_idle_balance() exists to bail out of load balancing if another task has woken up on the CPU currently in-charge of idle load balancing which is being processed in SCHED_SOFTIRQ context. Since the optimization mentioned above overloads the interpretation of TIF_NEED_RESCHED, check for idle_cpu() before going with the existing need_resched() check which can catch a genuine task wakeup on an idle CPU processing SCHED_SOFTIRQ from do_softirq_post_smp_call_flush(), as well as the case where ksoftirqd needs to be preempted as a result of new task wakeup or slice expiry. In case of PREEMPT_RT or threadirqs, although the idle load balancing may be inhibited in some cases on the ilb CPU, the fact that ksoftirqd is the only fair task going back to sleep will trigger a newidle balance on the CPU which will alleviate some imbalance if it exists if idle balance fails to do so. Fixes: b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241119054432.6405-4-kprateek.nayak@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14sched/core: Remove the unnecessary need_resched() check in nohz_csd_func()K Prateek Nayak
[ Upstream commit ea9cffc0a154124821531991d5afdd7e8b20d7aa ] The need_resched() check currently in nohz_csd_func() can be tracked to have been added in scheduler_ipi() back in 2011 via commit ca38062e57e9 ("sched: Use resched IPI to kick off the nohz idle balance") Since then, it has travelled quite a bit but it seems like an idle_cpu() check currently is sufficient to detect the need to bail out from an idle load balancing. To justify this removal, consider all the following case where an idle load balancing could race with a task wakeup: o Since commit f3dd3f674555b ("sched: Remove the limitation of WF_ON_CPU on wakelist if wakee cpu is idle") a target perceived to be idle (target_rq->nr_running == 0) will return true for ttwu_queue_cond(target) which will offload the task wakeup to the idle target via an IPI. In all such cases target_rq->ttwu_pending will be set to 1 before queuing the wake function. If an idle load balance races here, following scenarios are possible: - The CPU is not in TIF_POLLING_NRFLAG mode in which case an actual IPI is sent to the CPU to wake it out of idle. If the nohz_csd_func() queues before sched_ttwu_pending(), the idle load balance will bail out since idle_cpu(target) returns 0 since target_rq->ttwu_pending is 1. If the nohz_csd_func() is queued after sched_ttwu_pending() it should see rq->nr_running to be non-zero and bail out of idle load balancing. - The CPU is in TIF_POLLING_NRFLAG mode and instead of an actual IPI, the sender will simply set TIF_NEED_RESCHED for the target to put it out of idle and flush_smp_call_function_queue() in do_idle() will execute the call function. Depending on the ordering of the queuing of nohz_csd_func() and sched_ttwu_pending(), the idle_cpu() check in nohz_csd_func() should either see target_rq->ttwu_pending = 1 or target_rq->nr_running to be non-zero if there is a genuine task wakeup racing with the idle load balance kick. o The waker CPU perceives the target CPU to be busy (targer_rq->nr_running != 0) but the CPU is in fact going idle and due to a series of unfortunate events, the system reaches a case where the waker CPU decides to perform the wakeup by itself in ttwu_queue() on the target CPU but target is concurrently selected for idle load balance (XXX: Can this happen? I'm not sure, but we'll consider the mother of all coincidences to estimate the worst case scenario). ttwu_do_activate() calls enqueue_task() which would increment "rq->nr_running" post which it calls wakeup_preempt() which is responsible for setting TIF_NEED_RESCHED (via a resched IPI or by setting TIF_NEED_RESCHED on a TIF_POLLING_NRFLAG idle CPU) The key thing to note in this case is that rq->nr_running is already non-zero in case of a wakeup before TIF_NEED_RESCHED is set which would lead to idle_cpu() check returning false. In all cases, it seems that need_resched() check is unnecessary when checking for idle_cpu() first since an impending wakeup racing with idle load balancer will either set the "rq->ttwu_pending" or indicate a newly woken task via "rq->nr_running". Chasing the reason why this check might have existed in the first place, I came across Peter's suggestion on the fist iteration of Suresh's patch from 2011 [1] where the condition to raise the SCHED_SOFTIRQ was: sched_ttwu_do_pending(list); if (unlikely((rq->idle == current) && rq->nohz_balance_kick && !need_resched())) raise_softirq_irqoff(SCHED_SOFTIRQ); Since the condition to raise the SCHED_SOFIRQ was preceded by sched_ttwu_do_pending() (which is equivalent of sched_ttwu_pending()) in the current upstream kernel, the need_resched() check was necessary to catch a newly queued task. Peter suggested modifying it to: if (idle_cpu() && rq->nohz_balance_kick && !need_resched()) raise_softirq_irqoff(SCHED_SOFTIRQ); where idle_cpu() seems to have replaced "rq->idle == current" check. Even back then, the idle_cpu() check would have been sufficient to catch a new task being enqueued. Since commit b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()") overloads the interpretation of TIF_NEED_RESCHED for TIF_POLLING_NRFLAG idling, remove the need_resched() check in nohz_csd_func() to raise SCHED_SOFTIRQ based on Peter's suggestion. Fixes: b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()") Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241119054432.6405-3-kprateek.nayak@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14tracing: Use atomic64_inc_return() in trace_clock_counter()Uros Bizjak
[ Upstream commit eb887c4567d1b0e7684c026fe7df44afa96589e6 ] Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref) to use optimized implementation and ease register pressure around the primitive for targets that implement optimized variant. Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241007085651.48544-1-ubizjak@gmail.com Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14tracing/ftrace: disable preemption in syscall probeMathieu Desnoyers
[ Upstream commit 13d750c2c03e9861e15268574ed2c239cca9c9d5 ] In preparation for allowing system call enter/exit instrumentation to handle page faults, make sure that ftrace can handle this change by explicitly disabling preemption within the ftrace system call tracepoint probes to respect the current expectations within ftrace ring buffer code. This change does not yet allow ftrace to take page faults per se within its probe, but allows its existing probes to adapt to the upcoming change. Cc: Michael Jeanson <mjeanson@efficios.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: bpf@vger.kernel.org Cc: Joel Fernandes <joel@joelfernandes.org> Link: https://lore.kernel.org/20241009010718.2050182-3-mathieu.desnoyers@efficios.com Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14dma-debug: fix a possible deadlock on radix_lockLevi Yun
[ Upstream commit 7543c3e3b9b88212fcd0aaf5cab5588797bdc7de ] radix_lock() shouldn't be held while holding dma_hash_entry[idx].lock otherwise, there's a possible deadlock scenario when dma debug API is called holding rq_lock(): CPU0 CPU1 CPU2 dma_free_attrs() check_unmap() add_dma_entry() __schedule() //out (A) rq_lock() get_hash_bucket() (A) dma_entry_hash check_sync() (A) radix_lock() (W) dma_entry_hash dma_entry_free() (W) radix_lock() // CPU2's one (W) rq_lock() CPU1 situation can happen when it extending radix tree and it tries to wake up kswapd via wake_all_kswapd(). CPU2 situation can happen while perf_event_task_sched_out() (i.e. dma sync operation is called while deleting perf_event using etm and etr tmc which are Arm Coresight hwtracing driver backends). To remove this possible situation, call dma_entry_free() after put_hash_bucket() in check_unmap(). Reported-by: Denis Nikitin <denik@chromium.org> Closes: https://lists.linaro.org/archives/list/coresight@lists.linaro.org/thread/2WMS7BBSF5OZYB63VT44U5YWLFP5HL6U/#RWM6MLQX5ANBTEQ2PRM7OXCBGCE6NPWU Signed-off-by: Levi Yun <yeoreum.yun@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14kcsan: Turn report_filterlist_lock into a raw_spinlockMarco Elver
[ Upstream commit 59458fa4ddb47e7891c61b4a928d13d5f5b00aa0 ] Ran Xiaokai reports that with a KCSAN-enabled PREEMPT_RT kernel, we can see splats like: | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 | in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1 | preempt_count: 10002, expected: 0 | RCU nest depth: 0, expected: 0 | no locks held by swapper/1/0. | irq event stamp: 156674 | hardirqs last enabled at (156673): [<ffffffff81130bd9>] do_idle+0x1f9/0x240 | hardirqs last disabled at (156674): [<ffffffff82254f84>] sysvec_apic_timer_interrupt+0x14/0xc0 | softirqs last enabled at (0): [<ffffffff81099f47>] copy_process+0xfc7/0x4b60 | softirqs last disabled at (0): [<0000000000000000>] 0x0 | Preemption disabled at: | [<ffffffff814a3e2a>] paint_ptr+0x2a/0x90 | CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.11.0+ #3 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 | Call Trace: | <IRQ> | dump_stack_lvl+0x7e/0xc0 | dump_stack+0x1d/0x30 | __might_resched+0x1a2/0x270 | rt_spin_lock+0x68/0x170 | kcsan_skip_report_debugfs+0x43/0xe0 | print_report+0xb5/0x590 | kcsan_report_known_origin+0x1b1/0x1d0 | kcsan_setup_watchpoint+0x348/0x650 | __tsan_unaligned_write1+0x16d/0x1d0 | hrtimer_interrupt+0x3d6/0x430 | __sysvec_apic_timer_interrupt+0xe8/0x3a0 | sysvec_apic_timer_interrupt+0x97/0xc0 | </IRQ> On a detected data race, KCSAN's reporting logic checks if it should filter the report. That list is protected by the report_filterlist_lock *non-raw* spinlock which may sleep on RT kernels. Since KCSAN may report data races in any context, convert it to a raw_spinlock. This requires being careful about when to allocate memory for the filter list itself which can be done via KCSAN's debugfs interface. Concurrent modification of the filter list via debugfs should be rare: the chosen strategy is to optimistically pre-allocate memory before the critical section and discard if unused. Link: https://lore.kernel.org/all/20240925143154.2322926-1-ranxiaokai627@163.com/ Reported-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Tested-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14bpf: fix OOB devmap writes when deleting elementsMaciej Fijalkowski
commit ab244dd7cf4c291f82faacdc50b45cc0f55b674d upstream. Jordy reported issue against XSKMAP which also applies to DEVMAP - the index used for accessing map entry, due to being a signed integer, causes the OOB writes. Fix is simple as changing the type from int to u32, however, when compared to XSKMAP case, one more thing needs to be addressed. When map is released from system via dev_map_free(), we iterate through all of the entries and an iterator variable is also an int, which implies OOB accesses. Again, change it to be u32. Example splat below: [ 160.724676] BUG: unable to handle page fault for address: ffffc8fc2c001000 [ 160.731662] #PF: supervisor read access in kernel mode [ 160.736876] #PF: error_code(0x0000) - not-present page [ 160.742095] PGD 0 P4D 0 [ 160.744678] Oops: Oops: 0000 [#1] PREEMPT SMP [ 160.749106] CPU: 1 UID: 0 PID: 520 Comm: kworker/u145:12 Not tainted 6.12.0-rc1+ #487 [ 160.757050] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [ 160.767642] Workqueue: events_unbound bpf_map_free_deferred [ 160.773308] RIP: 0010:dev_map_free+0x77/0x170 [ 160.777735] Code: 00 e8 fd 91 ed ff e8 b8 73 ed ff 41 83 7d 18 19 74 6e 41 8b 45 24 49 8b bd f8 00 00 00 31 db 85 c0 74 48 48 63 c3 48 8d 04 c7 <48> 8b 28 48 85 ed 74 30 48 8b 7d 18 48 85 ff 74 05 e8 b3 52 fa ff [ 160.796777] RSP: 0018:ffffc9000ee1fe38 EFLAGS: 00010202 [ 160.802086] RAX: ffffc8fc2c001000 RBX: 0000000080000000 RCX: 0000000000000024 [ 160.809331] RDX: 0000000000000000 RSI: 0000000000000024 RDI: ffffc9002c001000 [ 160.816576] RBP: 0000000000000000 R08: 0000000000000023 R09: 0000000000000001 [ 160.823823] R10: 0000000000000001 R11: 00000000000ee6b2 R12: dead000000000122 [ 160.831066] R13: ffff88810c928e00 R14: ffff8881002df405 R15: 0000000000000000 [ 160.838310] FS: 0000000000000000(0000) GS:ffff8897e0c40000(0000) knlGS:0000000000000000 [ 160.846528] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 160.852357] CR2: ffffc8fc2c001000 CR3: 0000000005c32006 CR4: 00000000007726f0 [ 160.859604] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 160.866847] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 160.874092] PKRU: 55555554 [ 160.876847] Call Trace: [ 160.879338] <TASK> [ 160.881477] ? __die+0x20/0x60 [ 160.884586] ? page_fault_oops+0x15a/0x450 [ 160.888746] ? search_extable+0x22/0x30 [ 160.892647] ? search_bpf_extables+0x5f/0x80 [ 160.896988] ? exc_page_fault+0xa9/0x140 [ 160.900973] ? asm_exc_page_fault+0x22/0x30 [ 160.905232] ? dev_map_free+0x77/0x170 [ 160.909043] ? dev_map_free+0x58/0x170 [ 160.912857] bpf_map_free_deferred+0x51/0x90 [ 160.917196] process_one_work+0x142/0x370 [ 160.921272] worker_thread+0x29e/0x3b0 [ 160.925082] ? rescuer_thread+0x4b0/0x4b0 [ 160.929157] kthread+0xd4/0x110 [ 160.932355] ? kthread_park+0x80/0x80 [ 160.936079] ret_from_fork+0x2d/0x50 [ 160.943396] ? kthread_park+0x80/0x80 [ 160.950803] ret_from_fork_asm+0x11/0x20 [ 160.958482] </TASK> Fixes: 546ac1ffb70d ("bpf: add devmap, a map for storing net device references") CC: stable@vger.kernel.org Reported-by: Jordy Zomer <jordyzomer@google.com> Suggested-by: Jordy Zomer <jordyzomer@google.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/r/20241122121030.716788-3-maciej.fijalkowski@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14tracing: Fix cmp_entries_dup() to respect sort() comparison rulesKuan-Wei Chiu
commit e63fbd5f6810ed756bbb8a1549c7d4132968baa9 upstream. The cmp_entries_dup() function used as the comparator for sort() violated the symmetry and transitivity properties required by the sorting algorithm. Specifically, it returned 1 whenever memcmp() was non-zero, which broke the following expectations: * Symmetry: If x < y, then y > x. * Transitivity: If x < y and y < z, then x < z. These violations could lead to incorrect sorting and failure to correctly identify duplicate elements. Fix the issue by directly returning the result of memcmp(), which adheres to the required comparison properties. Cc: stable@vger.kernel.org Fixes: 08d43a5fa063 ("tracing: Add lock-free tracing_map") Link: https://lore.kernel.org/20241203202228.1274403-1-visitorckw@gmail.com Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14bpf: Fix exact match conditions in trie_get_next_key()Hou Tao
[ Upstream commit 27abc7b3fa2e09bbe41e2924d328121546865eda ] trie_get_next_key() uses node->prefixlen == key->prefixlen to identify an exact match, However, it is incorrect because when the target key doesn't fully match the found node (e.g., node->prefixlen != matchlen), these two nodes may also have the same prefixlen. It will return expected result when the passed key exist in the trie. However when a recently-deleted key or nonexistent key is passed to trie_get_next_key(), it may skip keys and return incorrect result. Fix it by using node->prefixlen == matchlen to identify exact matches. When the condition is true after the search, it also implies node->prefixlen equals key->prefixlen, otherwise, the search would return NULL instead. Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map") Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20241206110622.1161752-6-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14bpf: Handle in-place update for full LPM trie correctlyHou Tao
[ Upstream commit 532d6b36b2bfac5514426a97a4df8d103d700d43 ] When a LPM trie is full, in-place updates of existing elements incorrectly return -ENOSPC. Fix this by deferring the check of trie->n_entries. For new insertions, n_entries must not exceed max_entries. However, in-place updates are allowed even when the trie is full. Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20241206110622.1161752-5-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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