syzbot


INFO: rcu detected stall in sys_unlink

Status: upstream: reported on 2024/01/23 10:50
Reported-by: syzbot+22bb0b3dbc38b0c7d00c@syzkaller.appspotmail.com
First crash: 153d, last: 7d19h
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_unlink (2) kernel 2 519d 603d 0/27 auto-obsoleted due to no activity on 2023/04/22 20:06
upstream INFO: rcu detected stall in sys_unlink (3) mm C error 27 2d09h 316d 0/27 upstream: reported C repro on 2023/08/13 23:42
upstream INFO: rcu detected stall in sys_unlink kasan mm 1 694d 694d 0/27 auto-obsoleted due to no activity on 2022/10/29 07:23
linux-5.15 INFO: rcu detected stall in sys_unlink 1 104d 104d 0/3 auto-obsoleted due to no activity on 2024/06/20 14:47
android-5-15 BUG: soft lockup in sys_unlink 7 46d 69d 0/2 premoderation: reported on 2024/04/16 22:56

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=6cfc/1/0x4000000000000000 softirq=19898/19898 fqs=0
	(detected by 0, t=10502 jiffies, g=25321, q=84 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6029 Comm: syz-executor.1 Not tainted 6.1.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:__lock_acquire+0xeeb/0x1f80
Code: cf 89 ca c1 c2 06 44 31 fa 01 c1 29 d0 89 d6 c1 c6 08 31 c6 01 ca 29 f1 89 f3 c1 c3 10 31 cb 01 d6 29 da 89 dd c1 c5 13 31 d5 <01> f3 29 ee 01 eb c1 c5 04 31 f5 48 c1 e5 20 48 c7 c0 e8 be 73 8e
RSP: 0018:ffffc900001e0a60 EFLAGS: 00000002
RAX: 000000000002e8cc RBX: 00000000d8d9e728 RCX: 0000000002ea1a3d
RDX: 000000002723247a RSI: 00000000fd12e5d5 RDI: dffffc0000000000
RBP: 000000001e65e2b5 R08: dffffc0000000000 R09: fffffbfff2093a73
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888026fe4658
R13: 0000000000000001 R14: ffff888026fe46a8 R15: 0000000000000b8d
FS:  0000555556509480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000207b6000 CR3: 000000005e5ac000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 advance_sched+0x47/0x970 net/sched/sch_taprio.c:700
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:347 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:357 [inline]
RIP: 0010:unwind_next_frame+0xc42/0x2220 arch/x86/kernel/unwind_orc.c:539
Code: 48 89 dd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 80 7c 05 00 00 74 08 48 89 df e8 b8 63 a5 00 48 89 5c 24 70 4c 89 6c 24 38 <49> 8b 5c 24 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 28 0f b6
RSP: 0018:ffffc9000aed7260 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc9000aed7350 RCX: ffffffff8e8be148
RDX: 1ffffffff1df6b9c RSI: 0000000000000000 RDI: dffffc0000000000
RBP: 1ffff920015dae6a R08: 0000000000000003 R09: ffffc9000aed7430
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc9000aed7340
R13: ffffffff8efb5ce6 R14: ffffc9000aed0000 R15: 1ffff920015dae69
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0x292/0x510 mm/slub.c:3683
 free_buffer_head+0x45/0xb0 fs/buffer.c:2915
 try_to_free_buffers+0x302/0x600 fs/buffer.c:2856
 block_invalidate_folio+0x67d/0xa00 fs/buffer.c:1526
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x1e3/0x5e0 mm/truncate.c:178
 truncate_inode_pages_range+0x2e6/0x1340 mm/truncate.c:368
 ext4_evict_inode+0x39c/0x1150 fs/ext4/inode.c:221
 evict+0x2a4/0x620 fs/inode.c:666
 do_unlinkat+0x509/0x820 fs/namei.c:4399
 __do_sys_unlink fs/namei.c:4440 [inline]
 __se_sys_unlink fs/namei.c:4438 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4438
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd22587c657
Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff9c53ec08 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd22587c657
RDX: 00007fff9c53ec30 RSI: 00007fff9c53ecc0 RDI: 00007fff9c53ecc0
RBP: 00007fff9c53ecc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff9c53fd70
R13: 00007fd2258d9636 R14: 0000000000036753 R15: 000000000000001c
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g25321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=10641
rcu: rcu_preempt kthread starved for 10502 jiffies! g25321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:26144 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6029 Comm: syz-executor.1 Not tainted 6.1.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:validate_chain+0x11/0x5950 kernel/locking/lockdep.c:3781
Code: c7 e8 be 73 8e e8 6f f4 76 00 eb 84 e8 58 fa 1f 09 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 <48> 81 ec 80 02 00 00 49 89 ce 89 54 24 60 48 89 7c 24 78 65 48 8b
RSP: 0018:ffffc900001e0a40 EFLAGS: 00000082
RAX: 1ffffffff2032a4c RBX: ffffffff90195260 RCX: da2e616334457c0f
RDX: 0000000000000001 RSI: ffff888026fe4688 RDI: ffff888026fe3b80
RBP: ffffc900001e0a70 R08: dffffc0000000000 R09: fffffbfff2093a45
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888026fe4658
R13: ffff888026fe3b80 R14: 0000000000000001 R15: 1ffff11004dfc8d5
FS:  0000555556509480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000207b6000 CR3: 000000005e5ac000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 advance_sched+0x6ec/0x970 net/sched/sch_taprio.c:753
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:347 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:357 [inline]
RIP: 0010:unwind_next_frame+0xc42/0x2220 arch/x86/kernel/unwind_orc.c:539
Code: 48 89 dd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 80 7c 05 00 00 74 08 48 89 df e8 b8 63 a5 00 48 89 5c 24 70 4c 89 6c 24 38 <49> 8b 5c 24 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 28 0f b6
RSP: 0018:ffffc9000aed7260 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc9000aed7350 RCX: ffffffff8e8be148
RDX: 1ffffffff1df6b9c RSI: 0000000000000000 RDI: dffffc0000000000
RBP: 1ffff920015dae6a R08: 0000000000000003 R09: ffffc9000aed7430
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc9000aed7340
R13: ffffffff8efb5ce6 R14: ffffc9000aed0000 R15: 1ffff920015dae69
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0x292/0x510 mm/slub.c:3683
 free_buffer_head+0x45/0xb0 fs/buffer.c:2915
 try_to_free_buffers+0x302/0x600 fs/buffer.c:2856
 block_invalidate_folio+0x67d/0xa00 fs/buffer.c:1526
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x1e3/0x5e0 mm/truncate.c:178
 truncate_inode_pages_range+0x2e6/0x1340 mm/truncate.c:368
 ext4_evict_inode+0x39c/0x1150 fs/ext4/inode.c:221
 evict+0x2a4/0x620 fs/inode.c:666
 do_unlinkat+0x509/0x820 fs/namei.c:4399
 __do_sys_unlink fs/namei.c:4440 [inline]
 __se_sys_unlink fs/namei.c:4438 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4438
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd22587c657
Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff9c53ec08 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd22587c657
RDX: 00007fff9c53ec30 RSI: 00007fff9c53ecc0 RDI: 00007fff9c53ecc0
RBP: 00007fff9c53ecc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff9c53fd70
R13: 00007fd2258d9636 R14: 0000000000036753 R15: 000000000000001c
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/17 04:31 linux-6.1.y eb44d83053d6 f429ab00 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2024/04/02 14:52 linux-6.1.y e5cd595e23c1 eb2966c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2024/01/23 10:49 linux-6.1.y 8fd7f4462453 1c0ecc51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
* Struck through repros no longer work on HEAD.