| Kernel | Title | Repro | Cause bisect | Fix bisect | Count | Last | Reported | Patched | Status |
|---|---|---|---|---|---|---|---|---|---|
| upstream | possible deadlock in userfaultfd_release | C | done | 137 | 1765d | 2008d | 12/26 | fixed on 2019/07/29 13:39 |
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| Kernel | Title | Repro | Cause bisect | Fix bisect | Count | Last | Reported | Patched | Status |
|---|---|---|---|---|---|---|---|---|---|
| upstream | possible deadlock in userfaultfd_release | C | done | 137 | 1765d | 2008d | 12/26 | fixed on 2019/07/29 13:39 |
kauditd_printk_skb: 5 callbacks suppressed
audit: type=1400 audit(1561146492.680:36): avc: denied { map } for pid=7815 comm="syz-executor672" path="/root/syz-executor672817080" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
========================================================
WARNING: possible irq lock inversion dependency detected
4.19.53+ #25 Not tainted
--------------------------------------------------------
syz-executor672/7816 just changed the state of lock:
0000000087978b0b (&ctx->fault_pending_wqh){+.+.}, at: spin_lock include/linux/spinlock.h:329 [inline]
0000000087978b0b (&ctx->fault_pending_wqh){+.+.}, at: userfaultfd_release+0x4d6/0x720 fs/userfaultfd.c:922
but this lock was taken by another, SOFTIRQ-safe lock in the past:
(&(&ctx->ctx_lock)->rlock){..-.}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Chain exists of:
&(&ctx->ctx_lock)->rlock --> &ctx->fd_wqh --> &ctx->fault_pending_wqh
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ctx->fault_pending_wqh);
local_irq_disable();
lock(&(&ctx->ctx_lock)->rlock);
lock(&ctx->fd_wqh);
<Interrupt>
lock(&(&ctx->ctx_lock)->rlock);
*** DEADLOCK ***
no locks held by syz-executor672/7816.
the shortest dependencies between 2nd lock and 1st lock:
-> (&(&ctx->ctx_lock)->rlock){..-.} ops: 2 {
IN-SOFTIRQ-W at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160
spin_lock_irq include/linux/spinlock.h:354 [inline]
free_ioctx_users+0x2d/0x490 fs/aio.c:614
percpu_ref_put_many include/linux/percpu-refcount.h:284 [inline]
percpu_ref_put include/linux/percpu-refcount.h:300 [inline]
percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline]
percpu_ref_switch_to_atomic_rcu+0x407/0x540 lib/percpu-refcount.c:158
__rcu_reclaim kernel/rcu/rcu.h:236 [inline]
rcu_do_batch kernel/rcu/tree.c:2584 [inline]
invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
__rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
rcu_process_callbacks+0xba0/0x1a30 kernel/rcu/tree.c:2881
__do_softirq+0x25c/0x921 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:372 [inline]
irq_exit+0x180/0x1d0 kernel/softirq.c:412
exiting_irq arch/x86/include/asm/apic.h:536 [inline]
smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1056
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:869
native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:556
default_idle_call+0x36/0x90 kernel/sched/idle.c:93
cpuidle_idle_call kernel/sched/idle.c:153 [inline]
do_idle+0x377/0x560 kernel/sched/idle.c:262
cpu_startup_entry+0xc8/0xe0 kernel/sched/idle.c:368
start_secondary+0x3e8/0x5b0 arch/x86/kernel/smpboot.c:271
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
INITIAL USE at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160
spin_lock_irq include/linux/spinlock.h:354 [inline]
aio_poll fs/aio.c:1739 [inline]
__io_submit_one fs/aio.c:1849 [inline]
io_submit_one+0xead/0x2eb0 fs/aio.c:1885
__do_sys_io_submit fs/aio.c:1929 [inline]
__se_sys_io_submit fs/aio.c:1900 [inline]
__x64_sys_io_submit+0x1aa/0x520 fs/aio.c:1900
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
}
... key at: [<ffffffff8a3813a0>] __key.50193+0x0/0x40
... acquired at:
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:329 [inline]
aio_poll fs/aio.c:1741 [inline]
__io_submit_one fs/aio.c:1849 [inline]
io_submit_one+0xef2/0x2eb0 fs/aio.c:1885
__do_sys_io_submit fs/aio.c:1929 [inline]
__se_sys_io_submit fs/aio.c:1900 [inline]
__x64_sys_io_submit+0x1aa/0x520 fs/aio.c:1900
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> (&ctx->fd_wqh){....} ops: 4 {
INITIAL USE at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
add_wait_queue+0x4c/0x170 kernel/sched/wait.c:22
aio_poll_queue_proc+0x9e/0x110 fs/aio.c:1704
poll_wait include/linux/poll.h:47 [inline]
userfaultfd_poll+0x91/0x210 fs/userfaultfd.c:971
vfs_poll include/linux/poll.h:86 [inline]
aio_poll fs/aio.c:1738 [inline]
__io_submit_one fs/aio.c:1849 [inline]
io_submit_one+0xe4b/0x2eb0 fs/aio.c:1885
__do_sys_io_submit fs/aio.c:1929 [inline]
__se_sys_io_submit fs/aio.c:1900 [inline]
__x64_sys_io_submit+0x1aa/0x520 fs/aio.c:1900
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
}
... key at: [<ffffffff8a381120>] __key.43730+0x0/0x40
... acquired at:
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:329 [inline]
userfaultfd_ctx_read fs/userfaultfd.c:1046 [inline]
userfaultfd_read+0x394/0x18c0 fs/userfaultfd.c:1204
__vfs_read+0x114/0x800 fs/read_write.c:416
vfs_read+0x194/0x3d0 fs/read_write.c:452
ksys_read+0x14f/0x2d0 fs/read_write.c:579
__do_sys_read fs/read_write.c:589 [inline]
__se_sys_read fs/read_write.c:587 [inline]
__x64_sys_read+0x73/0xb0 fs/read_write.c:587
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> (&ctx->fault_pending_wqh){+.+.} ops: 3 {
HARDIRQ-ON-W at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:329 [inline]
userfaultfd_release+0x4d6/0x720 fs/userfaultfd.c:922
__fput+0x2dd/0x8b0 fs/file_table.c:278
____fput+0x16/0x20 fs/file_table.c:309
task_work_run+0x145/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x933/0x2fa0 kernel/exit.c:876
do_group_exit+0x135/0x370 kernel/exit.c:979
get_signal+0x3ec/0x1fc0 kernel/signal.c:2574
do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
SOFTIRQ-ON-W at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:329 [inline]
userfaultfd_release+0x4d6/0x720 fs/userfaultfd.c:922
__fput+0x2dd/0x8b0 fs/file_table.c:278
____fput+0x16/0x20 fs/file_table.c:309
task_work_run+0x145/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x933/0x2fa0 kernel/exit.c:876
do_group_exit+0x135/0x370 kernel/exit.c:979
get_signal+0x3ec/0x1fc0 kernel/signal.c:2574
do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
INITIAL USE at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:329 [inline]
userfaultfd_ctx_read fs/userfaultfd.c:1046 [inline]
userfaultfd_read+0x394/0x18c0 fs/userfaultfd.c:1204
__vfs_read+0x114/0x800 fs/read_write.c:416
vfs_read+0x194/0x3d0 fs/read_write.c:452
ksys_read+0x14f/0x2d0 fs/read_write.c:579
__do_sys_read fs/read_write.c:589 [inline]
__se_sys_read fs/read_write.c:587 [inline]
__x64_sys_read+0x73/0xb0 fs/read_write.c:587
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
}
... key at: [<ffffffff8a3811e0>] __key.43727+0x0/0x40
... acquired at:
mark_lock_irq kernel/locking/lockdep.c:2755 [inline]
mark_lock+0x420/0x1370 kernel/locking/lockdep.c:3127
mark_irqflags kernel/locking/lockdep.c:3023 [inline]
__lock_acquire+0x6b5/0x48f0 kernel/locking/lockdep.c:3368
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:329 [inline]
userfaultfd_release+0x4d6/0x720 fs/userfaultfd.c:922
__fput+0x2dd/0x8b0 fs/file_table.c:278
____fput+0x16/0x20 fs/file_table.c:309
task_work_run+0x145/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x933/0x2fa0 kernel/exit.c:876
do_group_exit+0x135/0x370 kernel/exit.c:979
get_signal+0x3ec/0x1fc0 kernel/signal.c:2574
do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
stack backtrace:
CPU: 0 PID: 7816 Comm: syz-executor672 Not tainted 4.19.53+ #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_irq_inversion_bug.part.0+0x2c0/0x2cd kernel/locking/lockdep.c:2621
print_irq_inversion_bug kernel/locking/lockdep.c:2624 [inline]
check_usage_backwards.cold+0x1d/0x26 kernel/locking/lockdep.c:2670
mark_lock_irq kernel/locking/lockdep.c:2755 [inline]
mark_lock+0x420/0x1370 kernel/locking/lockdep.c:3127
mark_irqflags kernel/locking/lockdep.c:3023 [inline]
__lock_acquire+0x6b5/0x48f0 kernel/locking/lockdep.c:3368
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:329 [inline]
userfaultfd_release+0x4d6/0x720 fs/userfaultfd.c:922
__fput+0x2dd/0x8b0 fs/file_table.c:278
____fput+0x16/0x20 fs/file_table.c:309
task_work_run+0x145/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x933/0x2fa0 kernel/exit.c:876
do_group_exit+0x135/0x370 kernel/exit.c:979
get_signal+0x3ec/0x1fc0 kernel/signal.c:2574
do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441299
Code: e8 fc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 9b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd9b9f89c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 0000000000441299
RDX: 0000000000000080 RSI: 00000000200000c0 RDI: 0000000000000005
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000246 R12: 00000000004020c0
R13: 0000000000402150 R14: 0000000000000000 R15: 0000000000000000
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2019/06/21 19:53 | linux-4.19.y | 9f31eb60d7a2 | 34bf9440 | .config | console log | report | syz | C | ci2-linux-4-19 | |||
| 2019/06/21 17:08 | linux-4.19.y | 9f31eb60d7a2 | 34bf9440 | .config | console log | report | syz | C | ci2-linux-4-19 | |||
| 2019/06/17 06:07 | linux-4.19.y | 7aa823a959e1 | 442206d7 | .config | console log | report | syz | C | ci2-linux-4-19 | |||
| 2019/06/16 20:10 | linux-4.19.y | 7aa823a959e1 | 442206d7 | .config | console log | report | syz | C | ci2-linux-4-19 |