user/sven/linux.git/kernel, branch v6.11.5

fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks

2024-10-22T13:51:23Z

commit 2c02f7375e658ae93d57a31a66f91b62754ef8f1 upstream. The function graph infrastructure allocates a shadow stack for every task when enabled. This includes the idle tasks. The first time the function graph is invoked, the shadow stacks are created and never freed until the task exits. This includes the idle tasks. Only the idle tasks that were for online CPUs had their shadow stacks created when function graph tracing started. If function graph tracing is enabled and a CPU comes online, the idle task representing that CPU will not have its shadow stack created, and all function graph tracing for that idle task will be silently dropped. Instead, use the CPU hotplug mechanism to allocate the idle shadow stacks. This will include idle tasks for CPUs that come online during tracing. This issue can be reproduced by: # cd /sys/kernel/tracing # echo 0 > /sys/devices/system/cpu/cpu1/online # echo 0 > set_ftrace_pid # echo function_graph > current_tracer # echo 1 > options/funcgraph-proc # echo 1 > /sys/devices/system/cpu/cpu1 # grep '' per_cpu/cpu1/trace | head Before, nothing would show up. After: 1) -0 | 0.811 us | __enqueue_entity(); 1) -0 | 5.626 us | } /* enqueue_entity */ 1) -0 | | dl_server_update_idle_time() { 1) -0 | | dl_scaled_delta_exec() { 1) -0 | 0.450 us | arch_scale_cpu_capacity(); 1) -0 | 1.242 us | } 1) -0 | 1.908 us | } 1) -0 | | dl_server_start() { 1) -0 | | enqueue_dl_entity() { 1) -0 | | task_contending() { Note, if tracing stops and restarts, the old way would then initialize the onlined CPUs. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Mark Rutland Cc: Thomas Gleixner Link: https://lore.kernel.org/20241018214300.6df82178@rorschach Fixes: 868baf07b1a25 ("ftrace: Fix memory leak with function graph and cpu hotplug") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

posix-clock: Fix missing timespec64 check in pc_clock_settime()

2024-10-22T13:51:18Z

commit d8794ac20a299b647ba9958f6d657051fc51a540 upstream. As Andrew pointed out, it will make sense that the PTP core checked timespec64 struct's tv_sec and tv_nsec range before calling ptp->info->settime64(). As the man manual of clock_settime() said, if tp.tv_sec is negative or tp.tv_nsec is outside the range [0..999,999,999], it should return EINVAL, which include dynamic clocks which handles PTP clock, and the condition is consistent with timespec64_valid(). As Thomas suggested, timespec64_valid() only check the timespec is valid, but not ensure that the time is in a valid range, so check it ahead using timespec64_valid_strict() in pc_clock_settime() and return -EINVAL if not valid. There are some drivers that use tp->tv_sec and tp->tv_nsec directly to write registers without validity checks and assume that the higher layer has checked it, which is dangerous and will benefit from this, such as hclge_ptp_settime(), igb_ptp_settime_i210(), _rcar_gen4_ptp_settime(), and some drivers can remove the checks of itself. Cc: stable@vger.kernel.org Fixes: 0606f422b453 ("posix clocks: Introduce dynamic clocks") Acked-by: Richard Cochran Suggested-by: Andrew Lunn Suggested-by: Thomas Gleixner Signed-off-by: Jinjie Ruan Link: https://patch.msgid.link/20241009072302.1754567-2-ruanjinjie@huawei.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

kthread: unpark only parked kthread

2024-10-17T13:27:02Z

commit 214e01ad4ed7158cab66498810094fac5d09b218 upstream. Calling into kthread unparking unconditionally is mostly harmless when the kthread is already unparked. The wake up is then simply ignored because the target is not in TASK_PARKED state. However if the kthread is per CPU, the wake up is preceded by a call to kthread_bind() which expects the task to be inactive and in TASK_PARKED state, which obviously isn't the case if it is unparked. As a result, calling kthread_stop() on an unparked per-cpu kthread triggers such a warning: WARNING: CPU: 0 PID: 11 at kernel/kthread.c:525 __kthread_bind_mask kernel/kthread.c:525 kthread_stop+0x17a/0x630 kernel/kthread.c:707 destroy_workqueue+0x136/0xc40 kernel/workqueue.c:5810 wg_destruct+0x1e2/0x2e0 drivers/net/wireguard/device.c:257 netdev_run_todo+0xe1a/0x1000 net/core/dev.c:10693 default_device_exit_batch+0xa14/0xa90 net/core/dev.c:11769 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x89d/0xcc0 net/core/net_namespace.c:640 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Fix this with skipping unecessary unparking while stopping a kthread. Link: https://lkml.kernel.org/r/20240913214634.12557-1-frederic@kernel.org Fixes: 5c25b5ff89f0 ("workqueue: Tag bound workers with KTHREAD_IS_PER_CPU") Signed-off-by: Frederic Weisbecker Reported-by: syzbot+943d34fa3cf2191e3068@syzkaller.appspotmail.com Tested-by: syzbot+943d34fa3cf2191e3068@syzkaller.appspotmail.com Suggested-by: Thomas Gleixner Cc: Hillf Danton Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

rcu/nocb: Fix rcuog wake-up from offline softirq

2024-10-17T13:26:52Z

[ Upstream commit f7345ccc62a4b880cf76458db5f320725f28e400 ] After a CPU has set itself offline and before it eventually calls rcutree_report_cpu_dead(), there are still opportunities for callbacks to be enqueued, for example from a softirq. When that happens on NOCB, the rcuog wake-up is deferred through an IPI to an online CPU in order not to call into the scheduler and risk arming the RT-bandwidth after hrtimers have been migrated out and disabled. But performing a synchronized IPI from a softirq is buggy as reported in the following scenario: WARNING: CPU: 1 PID: 26 at kernel/smp.c:633 smp_call_function_single Modules linked in: rcutorture torture CPU: 1 UID: 0 PID: 26 Comm: migration/1 Not tainted 6.11.0-rc1-00012-g9139f93209d1 #1 Stopper: multi_cpu_stop+0x0/0x320 <- __stop_cpus+0xd0/0x120 RIP: 0010:smp_call_function_single swake_up_one_online __call_rcu_nocb_wake __call_rcu_common ? rcu_torture_one_read call_timer_fn __run_timers run_timer_softirq handle_softirqs irq_exit_rcu ? tick_handle_periodic sysvec_apic_timer_interrupt Fix this with forcing deferred rcuog wake up through the NOCB timer when the CPU is offline. The actual wake up will happen from rcutree_report_cpu_dead(). Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202409231644.4c55582d-lkp@intel.com Fixes: 9139f93209d1 ("rcu/nocb: Fix RT throttling hrtimer armed from offline CPU") Reviewed-by: "Joel Fernandes (Google)" Signed-off-by: Frederic Weisbecker Signed-off-by: Neeraj Upadhyay Signed-off-by: Sasha Levin

bpf: Prevent tail call between progs attached to different hooks

2024-10-17T13:26:34Z

[ Upstream commit 28ead3eaabc16ecc907cfb71876da028080f6356 ] bpf progs can be attached to kernel functions, and the attached functions can take different parameters or return different return values. If prog attached to one kernel function tail calls prog attached to another kernel function, the ctx access or return value verification could be bypassed. For example, if prog1 is attached to func1 which takes only 1 parameter and prog2 is attached to func2 which takes two parameters. Since verifier assumes the bpf ctx passed to prog2 is constructed based on func2's prototype, verifier allows prog2 to access the second parameter from the bpf ctx passed to it. The problem is that verifier does not prevent prog1 from passing its bpf ctx to prog2 via tail call. In this case, the bpf ctx passed to prog2 is constructed from func1 instead of func2, that is, the assumption for ctx access verification is bypassed. Another example, if BPF LSM prog1 is attached to hook file_alloc_security, and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier knows the return value rules for these two hooks, e.g. it is legal for bpf_lsm_audit_rule_known to return positive number 1, and it is illegal for file_alloc_security to return positive number. So verifier allows prog2 to return positive number 1, but does not allow prog1 to return positive number. The problem is that verifier does not prevent prog1 from calling prog2 via tail call. In this case, prog2's return value 1 will be used as the return value for prog1's hook file_alloc_security. That is, the return value rule is bypassed. This patch adds restriction for tail call to prevent such bypasses. Signed-off-by: Xu Kuohai Link: https://lore.kernel.org/r/20240719110059.797546-4-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Signed-off-by: Sasha Levin

bpf: Check percpu map value size first

2024-10-17T13:26:33Z

[ Upstream commit 1d244784be6b01162b732a5a7d637dfc024c3203 ] Percpu map is often used, but the map value size limit often ignored, like issue: https://github.com/iovisor/bcc/issues/2519. Actually, percpu map value size is bound by PCPU_MIN_UNIT_SIZE, so we can check the value size whether it exceeds PCPU_MIN_UNIT_SIZE first, like percpu map of local_storage. Maybe the error message seems clearer compared with "cannot allocate memory". Signed-off-by: Jinke Han Signed-off-by: Tao Chen Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240910144111.1464912-2-chen.dylane@gmail.com Signed-off-by: Sasha Levin

bpf: Call the missed btf_record_free() when map creation fails

2024-10-17T13:26:33Z

[ Upstream commit 87e9675a0dfd0bf4a36550e4a0e673038ec67aee ] When security_bpf_map_create() in map_create() fails, map_create() will call btf_put() and ->map_free() callback to free the map. It doesn't free the btf_record of map value, so add the missed btf_record_free() when map creation fails. However btf_record_free() needs to be called after ->map_free() just like bpf_map_free_deferred() did, because ->map_free() may use the btf_record to free the special fields in preallocated map value. So factor out bpf_map_free() helper to free the map, btf_record, and btf orderly and use the helper in both map_create() and bpf_map_free_deferred(). Signed-off-by: Hou Tao Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20240912012845.3458483-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

uprobes: fix kernel info leak via "[uprobes]" vma

2024-10-10T10:04:14Z

commit 34820304cc2cd1804ee1f8f3504ec77813d29c8e upstream. xol_add_vma() maps the uninitialized page allocated by __create_xol_area() into userspace. On some architectures (x86) this memory is readable even without VM_READ, VM_EXEC results in the same pgprot_t as VM_EXEC|VM_READ, although this doesn't really matter, debugger can read this memory anyway. Link: https://lore.kernel.org/all/20240929162047.GA12611@redhat.com/ Reported-by: Will Deacon Fixes: d4b3b6384f98 ("uprobes/core: Allocate XOL slots for uprobes use") Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) Signed-off-by: Oleg Nesterov Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Sasha Levin

close_range(): fix the logics in descriptor table trimming

2024-10-10T10:04:11Z

commit 678379e1d4f7443b170939525d3312cfc37bf86b upstream. Cloning a descriptor table picks the size that would cover all currently opened files. That's fine for clone() and unshare(), but for close_range() there's an additional twist - we clone before we close, and it would be a shame to have close_range(3, ~0U, CLOSE_RANGE_UNSHARE) leave us with a huge descriptor table when we are not going to keep anything past stderr, just because some large file descriptor used to be open before our call has taken it out. Unfortunately, it had been dealt with in an inherently racy way - sane_fdtable_size() gets a "don't copy anything past that" argument (passed via unshare_fd() and dup_fd()), close_range() decides how much should be trimmed and passes that to unshare_fd(). The problem is, a range that used to extend to the end of descriptor table back when close_range() had looked at it might very well have stuff grown after it by the time dup_fd() has allocated a new files_struct and started to figure out the capacity of fdtable to be attached to that. That leads to interesting pathological cases; at the very least it's a QoI issue, since unshare(CLONE_FILES) is atomic in a sense that it takes a snapshot of descriptor table one might have observed at some point. Since CLOSE_RANGE_UNSHARE close_range() is supposed to be a combination of unshare(CLONE_FILES) with plain close_range(), ending up with a weird state that would never occur with unshare(2) is confusing, to put it mildly. It's not hard to get rid of - all it takes is passing both ends of the range down to sane_fdtable_size(). There we are under ->files_lock, so the race is trivially avoided. So we do the following: * switch close_files() from calling unshare_fd() to calling dup_fd(). * undo the calling convention change done to unshare_fd() in 60997c3d45d9 "close_range: add CLOSE_RANGE_UNSHARE" * introduce struct fd_range, pass a pointer to that to dup_fd() and sane_fdtable_size() instead of "trim everything past that point" they are currently getting. NULL means "we are not going to be punching any holes"; NR_OPEN_MAX is gone. * make sane_fdtable_size() use find_last_bit() instead of open-coding it; it's easier to follow that way. * while we are at it, have dup_fd() report errors by returning ERR_PTR(), no need to use a separate int *errorp argument. Fixes: 60997c3d45d9 "close_range: add CLOSE_RANGE_UNSHARE" Cc: stable@vger.kernel.org Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

tracing/timerlat: Fix duplicated kthread creation due to CPU online/offline

2024-10-10T10:04:10Z

commit 0bb0a5c12ecf36ad561542bbb95f96355e036a02 upstream. osnoise_hotplug_workfn() is the asynchronous online callback for "trace/osnoise:online". It may be congested when a CPU goes online and offline repeatedly and is invoked for multiple times after a certain online. This will lead to kthread leak and timer corruption. Add a check in start_kthread() to prevent this situation. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20240924094515.3561410-2-liwei391@huawei.com Fixes: c8895e271f79 ("trace/osnoise: Support hotplug operations") Signed-off-by: Wei Li Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman