* possible deadlock in lock_timer_base @ 2021-01-03 6:59 syzbot [not found] ` <20210103094904.14908-1-hdanton@sina.com> 2024-03-19 10:33 ` [syzbot] [batman?] [bpf?] " syzbot 0 siblings, 2 replies; 7+ messages in thread From: syzbot @ 2021-01-03 6:59 UTC (permalink / raw) To: akpm, christian, linux-kernel, shakeelb, syzkaller-bugs Hello, syzbot found the following issue on: HEAD commit: d7a03a44 Add linux-next specific files for 20201223 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=155fb7b7500000 kernel config: https://syzkaller.appspot.com/x/.config?x=ea251547cbb170c5 dashboard link: https://syzkaller.appspot.com/bug?extid=8983d6d4f7df556be565 compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8983d6d4f7df556be565@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected 5.10.0-next-20201223-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/9817 is trying to acquire lock: ffffffff8b48b998 (allocation_wait.lock){..-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 but task is already holding lock: ffff8880b9e24898 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:944 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&base->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:944 __mod_timer+0x398/0xe30 kernel/time/timer.c:1017 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1655 queue_delayed_work_on+0xd1/0xe0 kernel/workqueue.c:1680 psi_task_change+0x142/0x220 kernel/sched/psi.c:807 psi_enqueue kernel/sched/stats.h:82 [inline] enqueue_task kernel/sched/core.c:1592 [inline] activate_task kernel/sched/core.c:1615 [inline] wake_up_new_task+0x9f2/0xdd0 kernel/sched/core.c:3834 kernel_clone+0x1f0/0xab0 kernel/fork.c:2489 kernel_thread+0xb5/0xf0 kernel/fork.c:2517 rest_init+0x23/0x388 init/main.c:687 start_kernel+0x470/0x491 init/main.c:1064 secondary_startup_64_no_verify+0xb0/0xbb -> #2 (&rq->lock){-.-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 rq_lock kernel/sched/sched.h:1318 [inline] task_fork_fair+0x74/0x4d0 kernel/sched/fair.c:10767 sched_fork+0x3fc/0xbd0 kernel/sched/core.c:3764 copy_process+0x1d61/0x6fc0 kernel/fork.c:2070 kernel_clone+0xe7/0xab0 kernel/fork.c:2465 kernel_thread+0xb5/0xf0 kernel/fork.c:2517 rest_init+0x23/0x388 init/main.c:687 start_kernel+0x470/0x491 init/main.c:1064 secondary_startup_64_no_verify+0xb0/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 try_to_wake_up+0x98/0x13b0 kernel/sched/core.c:3335 autoremove_wake_function+0x12/0x140 kernel/sched/wait.c:404 __wake_up_common+0x147/0x650 kernel/sched/wait.c:108 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:138 __kfence_alloc+0xa0/0xbc0 mm/kfence/core.c:710 kfence_alloc include/linux/kfence.h:108 [inline] slab_alloc_node mm/slub.c:2826 [inline] kmem_cache_alloc_node_trace+0x28d/0x3d0 mm/slub.c:2953 kmalloc_node include/linux/slab.h:570 [inline] kzalloc_node include/linux/slab.h:693 [inline] alloc_worker kernel/workqueue.c:1826 [inline] create_worker+0xfe/0x6d0 kernel/workqueue.c:1923 maybe_create_worker kernel/workqueue.c:2094 [inline] manage_workers kernel/workqueue.c:2146 [inline] worker_thread+0xaef/0x1120 kernel/workqueue.c:2393 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 -> #0 (allocation_wait.lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:2868 [inline] check_prevs_add kernel/locking/lockdep.c:2993 [inline] validate_chain kernel/locking/lockdep.c:3608 [inline] __lock_acquire+0x2ade/0x5500 kernel/locking/lockdep.c:4832 lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 __kfence_alloc+0xa0/0xbc0 mm/kfence/core.c:710 kfence_alloc include/linux/kfence.h:108 [inline] slab_alloc_node mm/slub.c:2826 [inline] slab_alloc mm/slub.c:2911 [inline] kmem_cache_alloc+0x259/0x470 mm/slub.c:2916 kmem_cache_zalloc include/linux/slab.h:672 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:171 __debug_object_init+0x7a/0xd10 lib/debugobjects.c:560 debug_object_init lib/debugobjects.c:615 [inline] debug_object_activate+0x32c/0x3e0 lib/debugobjects.c:701 debug_timer_activate kernel/time/timer.c:727 [inline] __mod_timer+0x77d/0xe30 kernel/time/timer.c:1048 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1655 queue_delayed_work_on+0xd1/0xe0 kernel/workqueue.c:1680 queue_delayed_work include/linux/workqueue.h:522 [inline] schedule_delayed_work include/linux/workqueue.h:626 [inline] unaccount_event kernel/events/core.c:4703 [inline] _free_event+0xf49/0x1300 kernel/events/core.c:4812 put_event kernel/events/core.c:4935 [inline] perf_event_release_kernel+0xa24/0xe00 kernel/events/core.c:5050 perf_release+0x33/0x40 kernel/events/core.c:5060 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Chain exists of: allocation_wait.lock --> &rq->lock --> &base->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(&rq->lock); lock(&base->lock); lock(allocation_wait.lock); *** DEADLOCK *** 1 lock held by syz-executor.0/9817: #0: ffff8880b9e24898 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:944 stack backtrace: CPU: 0 PID: 9817 Comm: syz-executor.0 Not tainted 5.10.0-next-20201223-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2117 check_prev_add kernel/locking/lockdep.c:2868 [inline] check_prevs_add kernel/locking/lockdep.c:2993 [inline] validate_chain kernel/locking/lockdep.c:3608 [inline] __lock_acquire+0x2ade/0x5500 kernel/locking/lockdep.c:4832 lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 __kfence_alloc+0xa0/0xbc0 mm/kfence/core.c:710 kfence_alloc include/linux/kfence.h:108 [inline] slab_alloc_node mm/slub.c:2826 [inline] slab_alloc mm/slub.c:2911 [inline] kmem_cache_alloc+0x259/0x470 mm/slub.c:2916 kmem_cache_zalloc include/linux/slab.h:672 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:171 __debug_object_init+0x7a/0xd10 lib/debugobjects.c:560 debug_object_init lib/debugobjects.c:615 [inline] debug_object_activate+0x32c/0x3e0 lib/debugobjects.c:701 debug_timer_activate kernel/time/timer.c:727 [inline] __mod_timer+0x77d/0xe30 kernel/time/timer.c:1048 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1655 queue_delayed_work_on+0xd1/0xe0 kernel/workqueue.c:1680 queue_delayed_work include/linux/workqueue.h:522 [inline] schedule_delayed_work include/linux/workqueue.h:626 [inline] unaccount_event kernel/events/core.c:4703 [inline] _free_event+0xf49/0x1300 kernel/events/core.c:4812 put_event kernel/events/core.c:4935 [inline] perf_event_release_kernel+0xa24/0xe00 kernel/events/core.c:5050 perf_release+0x33/0x40 kernel/events/core.c:5060 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x417bf1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 a4 1a 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffe977a18a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000417bf1 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000ab3 R09: 00000000e0282ab7 R10: 00007ffe977a1980 R11: 0000000000000293 R12: 000000000119ca00 R13: 000000000119ca00 R14: 00000000000003e8 R15: 000000000119bf8c --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 7+ messages in thread
[parent not found: <20210103094904.14908-1-hdanton@sina.com>]
* Re: possible deadlock in lock_timer_base [not found] ` <20210103094904.14908-1-hdanton@sina.com> @ 2021-01-04 10:54 ` Marco Elver 0 siblings, 0 replies; 7+ messages in thread From: Marco Elver @ 2021-01-04 10:54 UTC (permalink / raw) To: Hillf Danton Cc: syzbot, Andrew Morton, LKML, Alexander Potapenko, Dmitry Vyukov, syzkaller-bugs On Sun, 3 Jan 2021 at 10:49, Hillf Danton <hdanton@sina.com> wrote: > > Sat, 02 Jan 2021 22:59:11 -0800 > > syzbot found the following issue on: > > > > HEAD commit: d7a03a44 Add linux-next specific files for 20201223 > > git tree: linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=155fb7b7500000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=ea251547cbb170c5 > > dashboard link: https://syzkaller.appspot.com/bug?extid=8983d6d4f7df556be565 > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+8983d6d4f7df556be565@syzkaller.appspotmail.com > > > > ====================================================== > > WARNING: possible circular locking dependency detected > > 5.10.0-next-20201223-syzkaller #0 Not tainted > > ------------------------------------------------------ > > syz-executor.0/9817 is trying to acquire lock: > > ffffffff8b48b998 (allocation_wait.lock){..-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 > > > > but task is already holding lock: > > ffff8880b9e24898 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:944 > > > > which lock already depends on the new lock. > > > > > > the existing dependency chain (in reverse order) is: > > > > -> #3 (&base->lock){-.-.}-{2:2}: > > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 > > lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:944 > > __mod_timer+0x398/0xe30 kernel/time/timer.c:1017 > > __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1655 > > queue_delayed_work_on+0xd1/0xe0 kernel/workqueue.c:1680 > > psi_task_change+0x142/0x220 kernel/sched/psi.c:807 > > psi_enqueue kernel/sched/stats.h:82 [inline] > > enqueue_task kernel/sched/core.c:1592 [inline] > > activate_task kernel/sched/core.c:1615 [inline] > > wake_up_new_task+0x9f2/0xdd0 kernel/sched/core.c:3834 > > kernel_clone+0x1f0/0xab0 kernel/fork.c:2489 > > kernel_thread+0xb5/0xf0 kernel/fork.c:2517 > > rest_init+0x23/0x388 init/main.c:687 > > start_kernel+0x470/0x491 init/main.c:1064 > > secondary_startup_64_no_verify+0xb0/0xbb > > > > -> #2 (&rq->lock){-.-.}-{2:2}: > > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > > rq_lock kernel/sched/sched.h:1318 [inline] > > task_fork_fair+0x74/0x4d0 kernel/sched/fair.c:10767 > > sched_fork+0x3fc/0xbd0 kernel/sched/core.c:3764 > > copy_process+0x1d61/0x6fc0 kernel/fork.c:2070 > > kernel_clone+0xe7/0xab0 kernel/fork.c:2465 > > kernel_thread+0xb5/0xf0 kernel/fork.c:2517 > > rest_init+0x23/0x388 init/main.c:687 > > start_kernel+0x470/0x491 init/main.c:1064 > > secondary_startup_64_no_verify+0xb0/0xbb > > > > -> #1 (&p->pi_lock){-.-.}-{2:2}: > > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 > > try_to_wake_up+0x98/0x13b0 kernel/sched/core.c:3335 > > autoremove_wake_function+0x12/0x140 kernel/sched/wait.c:404 > > __wake_up_common+0x147/0x650 kernel/sched/wait.c:108 > > __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:138 > > __kfence_alloc+0xa0/0xbc0 mm/kfence/core.c:710 > > kfence_alloc include/linux/kfence.h:108 [inline] > > slab_alloc_node mm/slub.c:2826 [inline] > > kmem_cache_alloc_node_trace+0x28d/0x3d0 mm/slub.c:2953 > > kmalloc_node include/linux/slab.h:570 [inline] > > kzalloc_node include/linux/slab.h:693 [inline] > > alloc_worker kernel/workqueue.c:1826 [inline] > > create_worker+0xfe/0x6d0 kernel/workqueue.c:1923 > > maybe_create_worker kernel/workqueue.c:2094 [inline] > > manage_workers kernel/workqueue.c:2146 [inline] > > worker_thread+0xaef/0x1120 kernel/workqueue.c:2393 > > kthread+0x3b1/0x4a0 kernel/kthread.c:292 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 > > > > -> #0 (allocation_wait.lock){..-.}-{2:2}: > > check_prev_add kernel/locking/lockdep.c:2868 [inline] > > check_prevs_add kernel/locking/lockdep.c:2993 [inline] > > validate_chain kernel/locking/lockdep.c:3608 [inline] > > __lock_acquire+0x2ade/0x5500 kernel/locking/lockdep.c:4832 > > lock_acquire kernel/locking/lockdep.c:5437 [inline] > > lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 > > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 > > __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 > > __kfence_alloc+0xa0/0xbc0 mm/kfence/core.c:710 > > kfence_alloc include/linux/kfence.h:108 [inline] > > slab_alloc_node mm/slub.c:2826 [inline] > > slab_alloc mm/slub.c:2911 [inline] > > kmem_cache_alloc+0x259/0x470 mm/slub.c:2916 > > kmem_cache_zalloc include/linux/slab.h:672 [inline] > > fill_pool+0x264/0x5c0 lib/debugobjects.c:171 > > __debug_object_init+0x7a/0xd10 lib/debugobjects.c:560 > > debug_object_init lib/debugobjects.c:615 [inline] > > debug_object_activate+0x32c/0x3e0 lib/debugobjects.c:701 > > debug_timer_activate kernel/time/timer.c:727 [inline] > > __mod_timer+0x77d/0xe30 kernel/time/timer.c:1048 > > __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1655 > > queue_delayed_work_on+0xd1/0xe0 kernel/workqueue.c:1680 > > queue_delayed_work include/linux/workqueue.h:522 [inline] > > schedule_delayed_work include/linux/workqueue.h:626 [inline] > > unaccount_event kernel/events/core.c:4703 [inline] > > _free_event+0xf49/0x1300 kernel/events/core.c:4812 > > put_event kernel/events/core.c:4935 [inline] > > perf_event_release_kernel+0xa24/0xe00 kernel/events/core.c:5050 > > perf_release+0x33/0x40 kernel/events/core.c:5060 > > __fput+0x283/0x920 fs/file_table.c:280 > > task_work_run+0xdd/0x190 kernel/task_work.c:140 > > tracehook_notify_resume include/linux/tracehook.h:189 [inline] > > exit_to_user_mode_loop kernel/entry/common.c:174 [inline] > > exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201 > > __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] > > syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > other info that might help us debug this: > > > > Chain exists of: > > allocation_wait.lock --> &rq->lock --> &base->lock > > > > Possible unsafe locking scenario: > > > > CPU0 CPU1 > > ---- ---- > > lock(&base->lock); > > lock(&rq->lock); > > lock(&base->lock); > > lock(allocation_wait.lock); > > > > *** DEADLOCK *** > > > > 1 lock held by syz-executor.0/9817: > > #0: ffff8880b9e24898 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:944 > > > > stack backtrace: > > CPU: 0 PID: 9817 Comm: syz-executor.0 Not tainted 5.10.0-next-20201223-syzkaller #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > Call Trace: > > __dump_stack lib/dump_stack.c:79 [inline] > > dump_stack+0x107/0x163 lib/dump_stack.c:120 > > check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2117 > > check_prev_add kernel/locking/lockdep.c:2868 [inline] > > check_prevs_add kernel/locking/lockdep.c:2993 [inline] > > validate_chain kernel/locking/lockdep.c:3608 [inline] > > __lock_acquire+0x2ade/0x5500 kernel/locking/lockdep.c:4832 > > lock_acquire kernel/locking/lockdep.c:5437 [inline] > > lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 > > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 > > __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 > > __kfence_alloc+0xa0/0xbc0 mm/kfence/core.c:710 > > kfence_alloc include/linux/kfence.h:108 [inline] > > slab_alloc_node mm/slub.c:2826 [inline] > > slab_alloc mm/slub.c:2911 [inline] > > kmem_cache_alloc+0x259/0x470 mm/slub.c:2916 > > kmem_cache_zalloc include/linux/slab.h:672 [inline] > > fill_pool+0x264/0x5c0 lib/debugobjects.c:171 > > __debug_object_init+0x7a/0xd10 lib/debugobjects.c:560 > > debug_object_init lib/debugobjects.c:615 [inline] > > debug_object_activate+0x32c/0x3e0 lib/debugobjects.c:701 > > debug_timer_activate kernel/time/timer.c:727 [inline] > > __mod_timer+0x77d/0xe30 kernel/time/timer.c:1048 > > __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1655 > > queue_delayed_work_on+0xd1/0xe0 kernel/workqueue.c:1680 > > queue_delayed_work include/linux/workqueue.h:522 [inline] > > schedule_delayed_work include/linux/workqueue.h:626 [inline] > > unaccount_event kernel/events/core.c:4703 [inline] > > _free_event+0xf49/0x1300 kernel/events/core.c:4812 > > put_event kernel/events/core.c:4935 [inline] > > perf_event_release_kernel+0xa24/0xe00 kernel/events/core.c:5050 > > perf_release+0x33/0x40 kernel/events/core.c:5060 > > __fput+0x283/0x920 fs/file_table.c:280 > > task_work_run+0xdd/0x190 kernel/task_work.c:140 > > tracehook_notify_resume include/linux/tracehook.h:189 [inline] > > exit_to_user_mode_loop kernel/entry/common.c:174 [inline] > > exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201 > > __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] > > syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > RIP: 0033:0x417bf1 > > Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 a4 1a 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 > > RSP: 002b:00007ffe977a18a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 > > RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000417bf1 > > RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000003 > > RBP: 0000000000000001 R08: 0000000000000ab3 R09: 00000000e0282ab7 > > R10: 00007ffe977a1980 R11: 0000000000000293 R12: 000000000119ca00 > > R13: 000000000119ca00 R14: 00000000000003e8 R15: 000000000119bf8c > > To avoid ttwu, open code wait_event_timeout(). Thanks, I'll send a patch. > --- a/mm/kfence/core.c > +++ b/mm/kfence/core.c > @@ -94,9 +94,6 @@ DEFINE_STATIC_KEY_FALSE(kfence_allocatio > /* Gates the allocation, ensuring only one succeeds in a given period. */ > static atomic_t allocation_gate = ATOMIC_INIT(1); > > -/* Wait queue to wake up allocation-gate timer task. */ > -static DECLARE_WAIT_QUEUE_HEAD(allocation_wait); > - > /* Statistics counters for debugfs. */ > enum kfence_counter_id { > KFENCE_COUNTER_ALLOCATED, > @@ -586,6 +583,8 @@ late_initcall(kfence_debugfs_init); > static struct delayed_work kfence_timer; > static void toggle_allocation_gate(struct work_struct *work) > { > + unsigned long end; > + > if (!READ_ONCE(kfence_enabled)) > return; > > @@ -596,7 +595,11 @@ static void toggle_allocation_gate(struc > * Await an allocation. Timeout after 1 second, in case the kernel stops > * doing allocations, to avoid stalling this worker task for too long. > */ > - wait_event_timeout(allocation_wait, atomic_read(&allocation_gate) != 0, HZ); > + for (end = jiffies + HZ; jiffies < end;) { > + if (atomic_read(&allocation_gate) != 0) > + break; We need set_current_state(TASK_UNINTERRUPTIBLE) here, otherwise schedule_timeout() has no effect. I'll fix this... > + schedule_timeout(1); > + } __set_current_state(TASK_RUNNING); > /* Disable static key and reset timer. */ > static_branch_disable(&kfence_allocation_key); > @@ -707,7 +710,6 @@ void *__kfence_alloc(struct kmem_cache * > */ > if (atomic_read(&allocation_gate) || atomic_inc_return(&allocation_gate) > 1) > return NULL; > - wake_up(&allocation_wait); > > if (!READ_ONCE(kfence_enabled)) > return NULL; > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20210103094904.14908-1-hdanton%40sina.com. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [batman?] [bpf?] possible deadlock in lock_timer_base 2021-01-03 6:59 possible deadlock in lock_timer_base syzbot [not found] ` <20210103094904.14908-1-hdanton@sina.com> @ 2024-03-19 10:33 ` syzbot 2024-03-19 13:19 ` Sven Eckelmann 2024-03-23 22:46 ` Hillf Danton 1 sibling, 2 replies; 7+ messages in thread From: syzbot @ 2024-03-19 10:33 UTC (permalink / raw) To: a, akpm, andrii, ast, b.a.t.m.a.n, bpf, christian, daniel, davem, dvyukov, edumazet, elver, glider, hdanton, jakub, jannh, john.fastabend, kasan-dev, kuba, linux-kernel, linux-mm, mareklindner, mark.rutland, netdev, pabeni, shakeelb, sven, sw, syzkaller-bugs syzbot has found a reproducer for the following issue on: HEAD commit: 35c3e2791756 Revert "net: Re-use and set mono_delivery_tim.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=10569181180000 kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440 dashboard link: https://syzkaller.appspot.com/bug?extid=8983d6d4f7df556be565 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13d9fa4e180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=137afac9180000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/26b55a26fc12/disk-35c3e279.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/6f39fa55c828/vmlinux-35c3e279.xz kernel image: https://storage.googleapis.com/syzbot-assets/e1e0501539e6/bzImage-35c3e279.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8983d6d4f7df556be565@syzkaller.appspotmail.com ===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.8.0-syzkaller-05228-g35c3e2791756 #0 Not tainted ----------------------------------------------------- rcu_preempt/16 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire: ffff888021c65020 (&htab->buckets[i].lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888021c65020 (&htab->buckets[i].lock){+...}-{2:2}, at: sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939 and this task is already holding: ffff8880b952a758 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 which would create a new lock dependency: (&base->lock){-.-.}-{2:2} -> ( &htab->buckets[i].lock){+...}-{2:2} but this new dependency connects a HARDIRQ-irq-safe lock: (&base->lock){-.-.}-{2:2} ... which became HARDIRQ-irq-safe at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 add_timer_on+0x1e5/0x5c0 kernel/time/timer.c:1366 handle_irq_event_percpu kernel/irq/handle.c:195 [inline] handle_irq_event+0xad/0x1f0 kernel/irq/handle.c:210 handle_level_irq+0x3c5/0x6e0 kernel/irq/chip.c:648 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0x13a/0x230 arch/x86/kernel/irq.c:257 common_interrupt+0xa5/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 __setup_irq+0x1277/0x1cf0 kernel/irq/manage.c:1818 request_threaded_irq+0x2ab/0x380 kernel/irq/manage.c:2202 request_irq include/linux/interrupt.h:168 [inline] setup_default_timer_irq+0x25/0x60 arch/x86/kernel/time.c:70 x86_late_time_init+0x66/0xc0 arch/x86/kernel/time.c:94 start_kernel+0x3f3/0x500 init/main.c:1039 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490 common_startup_64+0x13e/0x147 to a HARDIRQ-irq-unsafe lock: (&htab->buckets[i].lock){+...}-{2:2} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_free+0x164/0x820 net/core/sock_map.c:1154 bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&htab->buckets[i].lock ); local_irq_disable(); lock(&base->lock); lock(&htab->buckets[i].lock ); <Interrupt> lock(&base->lock); *** DEADLOCK *** 2 locks held by rcu_preempt/16: #0: ffff8880b952a758 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 #1: ffffffff8e131920 (rcu_read_lock ){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] ){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] ){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] ){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&base->lock){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 add_timer_on+0x1e5/0x5c0 kernel/time/timer.c:1366 handle_irq_event_percpu kernel/irq/handle.c:195 [inline] handle_irq_event+0xad/0x1f0 kernel/irq/handle.c:210 handle_level_irq+0x3c5/0x6e0 kernel/irq/chip.c:648 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0x13a/0x230 arch/x86/kernel/irq.c:257 common_interrupt+0xa5/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 __setup_irq+0x1277/0x1cf0 kernel/irq/manage.c:1818 request_threaded_irq+0x2ab/0x380 kernel/irq/manage.c:2202 request_irq include/linux/interrupt.h:168 [inline] setup_default_timer_irq+0x25/0x60 arch/x86/kernel/time.c:70 x86_late_time_init+0x66/0xc0 arch/x86/kernel/time.c:94 start_kernel+0x3f3/0x500 init/main.c:1039 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490 common_startup_64+0x13e/0x147 IN-SOFTIRQ-W at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170 __run_timer_base+0x103/0x8e0 kernel/time/timer.c:2418 run_timer_base kernel/time/timer.c:2428 [inline] run_timer_softirq+0x67/0x170 kernel/time/timer.c:2436 __do_softirq+0x2be/0x943 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 common_interrupt+0xaa/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 console_flush_all+0x9cd/0xec0 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3025 vprintk_emit+0x509/0x720 kernel/printk/printk.c:2292 _printk+0xd5/0x120 kernel/printk/printk.c:2317 cpu_select_mitigations+0x3c/0xa0 arch/x86/kernel/cpu/bugs.c:148 arch_cpu_finalize_init+0x20/0xa0 arch/x86/kernel/cpu/common.c:2325 start_kernel+0x402/0x500 init/main.c:1043 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490 common_startup_64+0x13e/0x147 INITIAL USE at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 __mod_timer+0x1ca/0xeb0 kernel/time/timer.c:1132 queue_delayed_work_on+0x15a/0x260 kernel/workqueue.c:2595 queue_delayed_work include/linux/workqueue.h:620 [inline] crng_reseed+0xe7/0x220 drivers/char/random.c:258 random_init+0x1a9/0x300 drivers/char/random.c:901 start_kernel+0x253/0x500 init/main.c:991 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490 common_startup_64+0x13e/0x147 } ... key at: [<ffffffff945023c0>] init_timer_cpu.__key+0x0/0x20 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&htab->buckets[i].lock ){+...}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_free+0x164/0x820 net/core/sock_map.c:1154 bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 INITIAL USE at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_free+0x164/0x820 net/core/sock_map.c:1154 bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 } ... key at: [<ffffffff94882300>] sock_hash_alloc.__key+0x0/0x20 ... acquired at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x396/0x550 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0xa0e/0xeb0 kernel/time/timer.c:1183 schedule_timeout+0x1b9/0x310 kernel/time/timer.c:2571 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 stack backtrace: CPU: 1 PID: 16 Comm: rcu_preempt Not tainted 6.8.0-syzkaller-05228-g35c3e2791756 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline] check_irq_usage kernel/locking/lockdep.c:2865 [inline] check_prev_add kernel/locking/lockdep.c:3138 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x4dc7/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x396/0x550 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0xa0e/0xeb0 kernel/time/timer.c:1183 schedule_timeout+0x1b9/0x310 kernel/time/timer.c:2571 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 </TASK> --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [batman?] [bpf?] possible deadlock in lock_timer_base 2024-03-19 10:33 ` [syzbot] [batman?] [bpf?] " syzbot @ 2024-03-19 13:19 ` Sven Eckelmann 2024-03-19 13:31 ` Aleksandr Nogikh 2024-03-23 22:46 ` Hillf Danton 1 sibling, 1 reply; 7+ messages in thread From: Sven Eckelmann @ 2024-03-19 13:19 UTC (permalink / raw) To: akpm, andrii, ast, b.a.t.m.a.n, bpf, christian, daniel, dvyukov, edumazet, elver, glider, hdanton, jakub, jannh, john.fastabend, kasan-dev, kuba, linux-kernel, linux-mm, mareklindner, mark.rutland, netdev, pabeni, shakeelb, syzkaller-bugs, syzbot [-- Attachment #1: Type: text/plain, Size: 1375 bytes --] On Tuesday, 19 March 2024 11:33:17 CET syzbot wrote: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 35c3e2791756 Revert "net: Re-use and set mono_delivery_tim.. > git tree: net > console output: https://syzkaller.appspot.com/x/log.txt?x=10569181180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440 > dashboard link: https://syzkaller.appspot.com/bug?extid=8983d6d4f7df556be565 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13d9fa4e180000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=137afac9180000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/26b55a26fc12/disk-35c3e279.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/6f39fa55c828/vmlinux-35c3e279.xz > kernel image: https://storage.googleapis.com/syzbot-assets/e1e0501539e6/bzImage-35c3e279.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+8983d6d4f7df556be565@syzkaller.appspotmail.com Sorry, this is a little bit off-topic. But how does sysbot figure out the subsystems (like "[batman?]"). Because neither the reproducer nor the backtrace nor the console output mention anything batman-adv related. Kind regards, Sven [-- Attachment #2: This is a digitally signed message part. --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [batman?] [bpf?] possible deadlock in lock_timer_base 2024-03-19 13:19 ` Sven Eckelmann @ 2024-03-19 13:31 ` Aleksandr Nogikh 0 siblings, 0 replies; 7+ messages in thread From: Aleksandr Nogikh @ 2024-03-19 13:31 UTC (permalink / raw) To: Sven Eckelmann Cc: akpm, andrii, ast, b.a.t.m.a.n, bpf, christian, daniel, dvyukov, edumazet, elver, glider, hdanton, jakub, jannh, john.fastabend, kasan-dev, kuba, linux-kernel, linux-mm, mareklindner, mark.rutland, netdev, pabeni, shakeelb, syzkaller-bugs, syzbot Hi Sven, On Tue, Mar 19, 2024 at 2:19 PM Sven Eckelmann <sven@narfation.org> wrote: > > On Tuesday, 19 March 2024 11:33:17 CET syzbot wrote: > > syzbot has found a reproducer for the following issue on: > > < ... > > > Sorry, this is a little bit off-topic. But how does sysbot figure out the > subsystems (like "[batman?]"). Because neither the reproducer nor the > backtrace nor the console output mention anything batman-adv related. Syzbot looks at several crash reports to determine the bug subsystems and in this case one of those crashes was pointing to net/batman-adv/multicast.c: https://syzkaller.appspot.com/text?tag=CrashReport&x=15afccb3280000 -- Aleksandr > > Kind regards, > Sven > > -- ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [batman?] [bpf?] possible deadlock in lock_timer_base 2024-03-19 10:33 ` [syzbot] [batman?] [bpf?] " syzbot 2024-03-19 13:19 ` Sven Eckelmann @ 2024-03-23 22:46 ` Hillf Danton 2024-03-24 2:51 ` syzbot 1 sibling, 1 reply; 7+ messages in thread From: Hillf Danton @ 2024-03-23 22:46 UTC (permalink / raw) To: syzbot; +Cc: linux-kernel, syzkaller-bugs #syz test https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git ea80e3ed09ab --- x/net/core/sock_map.c +++ y/net/core/sock_map.c @@ -932,11 +932,12 @@ static long sock_hash_delete_elem(struct struct bpf_shtab_bucket *bucket; struct bpf_shtab_elem *elem; int ret = -ENOENT; + unsigned long flags; hash = sock_hash_bucket_hash(key, key_size); bucket = sock_hash_select_bucket(htab, hash); - spin_lock_bh(&bucket->lock); + spin_lock_irqsave(&bucket->lock, flags); elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); if (elem) { hlist_del_rcu(&elem->node); @@ -944,7 +945,7 @@ static long sock_hash_delete_elem(struct sock_hash_free_elem(htab, elem); ret = 0; } - spin_unlock_bh(&bucket->lock); + spin_unlock_irqrestore(&bucket->lock, flags); return ret; } @@ -1143,6 +1144,8 @@ static void sock_hash_free(struct bpf_ma */ synchronize_rcu(); for (i = 0; i < htab->buckets_num; i++) { + unsigned long flags; + bucket = sock_hash_select_bucket(htab, i); /* We are racing with sock_hash_delete_from_link to @@ -1151,11 +1154,11 @@ static void sock_hash_free(struct bpf_ma * exists, psock exists and holds a ref to socket. That * lets us to grab a socket ref too. */ - spin_lock_bh(&bucket->lock); + spin_lock_irqsave(&bucket->lock, flags); hlist_for_each_entry(elem, &bucket->head, node) sock_hold(elem->sk); hlist_move_list(&bucket->head, &unlink_list); - spin_unlock_bh(&bucket->lock); + spin_unlock_irqrestore(&bucket->lock, flags); /* Process removed entries out of atomic context to * block for socket lock before deleting the psock's -- ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] [batman?] [bpf?] possible deadlock in lock_timer_base 2024-03-23 22:46 ` Hillf Danton @ 2024-03-24 2:51 ` syzbot 0 siblings, 0 replies; 7+ messages in thread From: syzbot @ 2024-03-24 2:51 UTC (permalink / raw) To: hdanton, linux-kernel, syzkaller-bugs Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-and-tested-by: syzbot+8983d6d4f7df556be565@syzkaller.appspotmail.com Tested on: commit: ea80e3ed net: ethernet: mtk_eth_soc: fix PPE hanging i.. git tree: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git console output: https://syzkaller.appspot.com/x/log.txt?x=12583185180000 kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440 dashboard link: https://syzkaller.appspot.com/bug?extid=8983d6d4f7df556be565 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 patch: https://syzkaller.appspot.com/x/patch.diff?x=12f9eaa5180000 Note: testing is done by a robot and is best-effort only. ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2024-03-24 2:51 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-01-03 6:59 possible deadlock in lock_timer_base syzbot [not found] ` <20210103094904.14908-1-hdanton@sina.com> 2021-01-04 10:54 ` Marco Elver 2024-03-19 10:33 ` [syzbot] [batman?] [bpf?] " syzbot 2024-03-19 13:19 ` Sven Eckelmann 2024-03-19 13:31 ` Aleksandr Nogikh 2024-03-23 22:46 ` Hillf Danton 2024-03-24 2:51 ` syzbot
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