user/sven/linux.git/kernel, branch v4.9.228

kernel/cpu_pm: Fix uninitted local in cpu_pm

2020-06-20T08:24:21Z

commit b5945214b76a1f22929481724ffd448000ede914 upstream. cpu_pm_notify() is basically a wrapper of notifier_call_chain(). notifier_call_chain() doesn't initialize *nr_calls to 0 before it starts incrementing it--presumably it's up to the callers to do this. Unfortunately the callers of cpu_pm_notify() don't init *nr_calls. This potentially means you could get too many or two few calls to CPU_PM_ENTER_FAILED or CPU_CLUSTER_PM_ENTER_FAILED depending on the luck of the stack. Let's fix this. Fixes: ab10023e0088 ("cpu_pm: Add cpu power management notifiers") Cc: stable@vger.kernel.org Cc: Rafael J. Wysocki Reviewed-by: Stephen Boyd Reviewed-by: Greg Kroah-Hartman Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20200504104917.v6.3.I2d44fc0053d019f239527a4e5829416714b7e299@changeid Signed-off-by: Bjorn Andersson Signed-off-by: Greg Kroah-Hartman

exit: Move preemption fixup up, move blocking operations down

2020-06-20T08:24:16Z

[ Upstream commit 586b58cac8b4683eb58a1446fbc399de18974e40 ] With CONFIG_DEBUG_ATOMIC_SLEEP=y and CONFIG_CGROUPS=y, kernel oopses in non-preemptible context look untidy; after the main oops, the kernel prints a "sleeping function called from invalid context" report because exit_signals() -> cgroup_threadgroup_change_begin() -> percpu_down_read() can sleep, and that happens before the preempt_count_set(PREEMPT_ENABLED) fixup. It looks like the same thing applies to profile_task_exit() and kcov_task_exit(). Fix it by moving the preemption fixup up and the calls to profile_task_exit() and kcov_task_exit() down. Fixes: 1dc0fffc48af ("sched/core: Robustify preemption leak checks") Signed-off-by: Jann Horn Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200305220657.46800-1-jannh@google.com Signed-off-by: Sasha Levin

kgdb: Prevent infinite recursive entries to the debugger

2020-06-20T08:24:14Z

[ Upstream commit 3ca676e4ca60d1834bb77535dafe24169cadacef ] If we detect that we recursively entered the debugger we should hack our I/O ops to NULL so that the panic() in the next line won't actually cause another recursion into the debugger. The first line of kgdb_panic() will check this and return. Signed-off-by: Douglas Anderson Reviewed-by: Daniel Thompson Link: https://lore.kernel.org/r/20200507130644.v4.6.I89de39f68736c9de610e6f241e68d8dbc44bc266@changeid Signed-off-by: Daniel Thompson Signed-off-by: Sasha Levin

perf: Add cond_resched() to task_function_call()

2020-06-20T08:24:13Z

commit 2ed6edd33a214bca02bd2b45e3fc3038a059436b upstream. Under rare circumstances, task_function_call() can repeatedly fail and cause a soft lockup. There is a slight race where the process is no longer running on the cpu we targeted by the time remote_function() runs. The code will simply try again. If we are very unlucky, this will continue to fail, until a watchdog fires. This can happen in a heavily loaded, multi-core virtual machine. Reported-by: syzbot+bb4935a5c09b5ff79940@syzkaller.appspotmail.com Signed-off-by: Barret Rhoden Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200414222920.121401-1-brho@google.com Signed-off-by: Greg Kroah-Hartman

sched/fair: Don't NUMA balance for kthreads

2020-06-20T08:24:08Z

[ Upstream commit 18f855e574d9799a0e7489f8ae6fd8447d0dd74a ] Stefano reported a crash with using SQPOLL with io_uring: BUG: kernel NULL pointer dereference, address: 00000000000003b0 CPU: 2 PID: 1307 Comm: io_uring-sq Not tainted 5.7.0-rc7 #11 RIP: 0010:task_numa_work+0x4f/0x2c0 Call Trace: task_work_run+0x68/0xa0 io_sq_thread+0x252/0x3d0 kthread+0xf9/0x130 ret_from_fork+0x35/0x40 which is task_numa_work() oopsing on current->mm being NULL. The task work is queued by task_tick_numa(), which checks if current->mm is NULL at the time of the call. But this state isn't necessarily persistent, if the kthread is using use_mm() to temporarily adopt the mm of a task. Change the task_tick_numa() check to exclude kernel threads in general, as it doesn't make sense to attempt ot balance for kthreads anyway. Reported-by: Stefano Garzarella Signed-off-by: Jens Axboe Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra Link: https://lore.kernel.org/r/865de121-8190-5d30-ece5-3b097dc74431@kernel.dk Signed-off-by: Sasha Levin

uprobes: ensure that uprobe->offset and ->ref_ctr_offset are properly aligned

2020-06-11T07:22:23Z

commit 013b2deba9a6b80ca02f4fafd7dedf875e9b4450 upstream. uprobe_write_opcode() must not cross page boundary; prepare_uprobe() relies on arch_uprobe_analyze_insn() which should validate "vaddr" but some architectures (csky, s390, and sparc) don't do this. We can remove the BUG_ON() check in prepare_uprobe() and validate the offset early in __uprobe_register(). The new IS_ALIGNED() check matches the alignment check in arch_prepare_kprobe() on supported architectures, so I think that all insns must be aligned to UPROBE_SWBP_INSN_SIZE. Another problem is __update_ref_ctr() which was wrong from the very beginning, it can read/write outside of kmap'ed page unless "vaddr" is aligned to sizeof(short), __uprobe_register() should check this too. Reported-by: Linus Torvalds Suggested-by: Linus Torvalds Signed-off-by: Oleg Nesterov Reviewed-by: Srikar Dronamraju Acked-by: Christian Borntraeger Tested-by: Sven Schnelle Cc: Steven Rostedt Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds [ check for ref_ctr_offset removed for backport - gregkh ] Signed-off-by: Greg Kroah-Hartman

kernel/relay.c: handle alloc_percpu returning NULL in relay_open

2020-06-11T07:22:20Z

commit 54e200ab40fc14c863bcc80a51e20b7906608fce upstream. alloc_percpu() may return NULL, which means chan->buf may be set to NULL. In that case, when we do *per_cpu_ptr(chan->buf, ...), we dereference an invalid pointer: BUG: Unable to handle kernel data access at 0x7dae0000 Faulting instruction address: 0xc0000000003f3fec ... NIP relay_open+0x29c/0x600 LR relay_open+0x270/0x600 Call Trace: relay_open+0x264/0x600 (unreliable) __blk_trace_setup+0x254/0x600 blk_trace_setup+0x68/0xa0 sg_ioctl+0x7bc/0x2e80 do_vfs_ioctl+0x13c/0x1300 ksys_ioctl+0x94/0x130 sys_ioctl+0x48/0xb0 system_call+0x5c/0x68 Check if alloc_percpu returns NULL. This was found by syzkaller both on x86 and powerpc, and the reproducer it found on powerpc is capable of hitting the issue as an unprivileged user. Fixes: 017c59c042d0 ("relay: Use per CPU constructs for the relay channel buffer pointers") Reported-by: syzbot+1e925b4b836afe85a1c6@syzkaller-ppc64.appspotmail.com Reported-by: syzbot+587b2421926808309d21@syzkaller-ppc64.appspotmail.com Reported-by: syzbot+58320b7171734bf79d26@syzkaller.appspotmail.com Reported-by: syzbot+d6074fb08bdb2e010520@syzkaller.appspotmail.com Signed-off-by: Daniel Axtens Signed-off-by: Andrew Morton Reviewed-by: Michael Ellerman Reviewed-by: Andrew Donnellan Acked-by: David Rientjes Cc: Akash Goel Cc: Andrew Donnellan Cc: Guenter Roeck Cc: Salvatore Bonaccorso Cc: [4.10+] Link: http://lkml.kernel.org/r/20191219121256.26480-1-dja@axtens.net Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

genirq/generic_pending: Do not lose pending affinity update

2020-06-03T06:16:47Z

commit a33a5d2d16cb84bea8d5f5510f3a41aa48b5c467 upstream. The generic pending interrupt mechanism moves interrupts from the interrupt handler on the original target CPU to the new destination CPU. This is required for x86 and ia64 due to the way the interrupt delivery and acknowledge works if the interrupts are not remapped. However that update can fail for various reasons. Some of them are valid reasons to discard the pending update, but the case, when the previous move has not been fully cleaned up is not a legit reason to fail. Check the return value of irq_do_set_affinity() for -EBUSY, which indicates a pending cleanup, and rearm the pending move in the irq dexcriptor so it's tried again when the next interrupt arrives. Fixes: 996c591227d9 ("x86/irq: Plug vector cleanup race") Signed-off-by: Thomas Gleixner Tested-by: Song Liu Cc: Joerg Roedel Cc: Peter Zijlstra Cc: Song Liu Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: stable@vger.kernel.org Cc: Mike Travis Cc: Borislav Petkov Cc: Tariq Toukan Cc: Guenter Roeck Link: https://lkml.kernel.org/r/20180604162224.386544292@linutronix.de Signed-off-by: Greg Kroah-Hartman

padata: purge get_cpu and reorder_via_wq from padata_do_serial

2020-05-27T14:41:53Z

[ Upstream commit 065cf577135a4977931c7a1e1edf442bfd9773dd ] With the removal of the padata timer, padata_do_serial no longer needs special CPU handling, so remove it. Signed-off-by: Daniel Jordan Cc: Herbert Xu Cc: Steffen Klassert Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Herbert Xu Signed-off-by: Daniel Jordan Signed-off-by: Sasha Levin

padata: initialize pd->cpu with effective cpumask

2020-05-27T14:41:52Z

[ Upstream commit ec9c7d19336ee98ecba8de80128aa405c45feebb ] Exercising CPU hotplug on a 5.2 kernel with recent padata fixes from cryptodev-2.6.git in an 8-CPU kvm guest... # modprobe tcrypt alg="pcrypt(rfc4106(gcm(aes)))" type=3 # echo 0 > /sys/devices/system/cpu/cpu1/online # echo c > /sys/kernel/pcrypt/pencrypt/parallel_cpumask # modprobe tcrypt mode=215 ...caused the following crash: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 2 PID: 134 Comm: kworker/2:2 Not tainted 5.2.0-padata-base+ #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0- Workqueue: pencrypt padata_parallel_worker RIP: 0010:padata_reorder+0xcb/0x180 ... Call Trace: padata_do_serial+0x57/0x60 pcrypt_aead_enc+0x3a/0x50 [pcrypt] padata_parallel_worker+0x9b/0xe0 process_one_work+0x1b5/0x3f0 worker_thread+0x4a/0x3c0 ... In padata_alloc_pd, pd->cpu is set using the user-supplied cpumask instead of the effective cpumask, and in this case cpumask_first picked an offline CPU. The offline CPU's reorder->list.next is NULL in padata_reorder because the list wasn't initialized in padata_init_pqueues, which only operates on CPUs in the effective mask. Fix by using the effective mask in padata_alloc_pd. Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder") Signed-off-by: Daniel Jordan Cc: Herbert Xu Cc: Steffen Klassert Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Herbert Xu Signed-off-by: Daniel Jordan Signed-off-by: Sasha Levin