syzbot


INFO: rcu detected stall in sys_mount

Status: upstream: reported on 2024/12/14 21:36
Reported-by: syzbot+4e7d075998b1d352e3bf@syzkaller.appspotmail.com
First crash: 59d, last: 36d
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_mount (6) ntfs C inconclusive 82 460d 1233d 0/28 auto-obsoleted due to no activity on 2024/02/18 04:52
upstream INFO: rcu detected stall in sys_mount (4) fs 2 1805d 1820d 0/28 auto-closed as invalid on 2020/06/02 15:48
upstream INFO: rcu detected stall in sys_mount (5) afs C done done 10 1595d 1616d 15/28 fixed on 2020/11/16 12:12
linux-5.15 INFO: rcu detected stall in sys_mount 2 61d 123d 0/3 upstream: reported on 2024/10/11 22:21
upstream INFO: rcu detected stall in sys_mount (3) kernel 6 1897d 1898d 0/28 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in sys_mount nfs 1 2303d 2302d 0/28 closed as invalid on 2018/10/29 13:47
upstream INFO: rcu detected stall in sys_mount (7) fs C inconclusive done 41 49d 292d 0/28 upstream: reported C repro on 2024/04/26 05:48
upstream INFO: rcu detected stall in sys_mount (2) exfat 1 2253d 2253d 0/28 closed as dup on 2018/12/12 21:01
android-5-15 BUG: soft lockup in sys_mount origin:lts C error 17 222d 300d 0/2 auto-obsoleted due to no activity on 2024/10/17 05:03

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=e28c/1/0x4000000000000000 softirq=33719/33719 fqs=6
	(detected by 1, t=10502 jiffies, g=50961, q=105 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8920 Comm: syz.1.868 Not tainted 6.1.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__kasan_check_read+0x0/0x10 mm/kasan/shadow.c:31
Code: d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c7 24 59 b9 8c eb 0a 48 c7 c7 5c 59 b9 8c 4c 89 fe e8 36 2b ce 08 31 db eb d7 cc cc <89> f6 48 8b 0c 24 31 d2 e9 d3 ec ff ff 0f 1f 00 89 f6 48 8b 0c 24
RSP: 0018:ffffc90000007ad8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8e9b0768
RBP: ffffc90000007c10 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 1ffff92000000f68
R13: ffffffff844923d9 R14: ffffc90000007c40 R15: dffffc0000000000
FS:  00007fe920c836c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e11fffc CR3: 000000001caae000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 cpumask_test_cpu include/linux/cpumask.h:444 [inline]
 cpu_online include/linux/cpumask.h:1030 [inline]
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0xc7/0xa20 kernel/locking/lockdep.c:5673
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x75/0x130 kernel/locking/spinlock.c:194
 debug_object_activate+0x2f9/0x4e0 lib/debugobjects.c:716
 debug_hrtimer_activate kernel/time/hrtimer.c:421 [inline]
 debug_activate kernel/time/hrtimer.c:476 [inline]
 enqueue_hrtimer+0x30/0x410 kernel/time/hrtimer.c:1085
 __run_hrtimer kernel/time/hrtimer.c:1706 [inline]
 __hrtimer_run_queues+0x728/0xe50 kernel/time/hrtimer.c:1753
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1815
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666
Code: 2b 00 74 08 4c 89 f7 e8 8f 8c 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc90004907320 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92000920e70 RCX: ffffffff97356103
RDX: dffffc0000000000 RSI: ffffffff8b0c14c0 RDI: ffffffff8b5e6840
RBP: ffffc90004907468 R08: dffffc0000000000 R09: fffffbfff275de0a
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000920e6c
R13: dffffc0000000000 R14: ffffc90004907380 R15: 0000000000000246
 __flush_workqueue+0x170/0x1610 kernel/workqueue.c:2812
 drain_workqueue+0xc5/0x390 kernel/workqueue.c:2977
 destroy_workqueue+0x7b/0xae0 kernel/workqueue.c:4423
 btrfs_destroy_workqueue+0x3e/0x2a0 fs/btrfs/async-thread.c:327
 btrfs_stop_all_workers+0x22b/0x300 fs/btrfs/disk-io.c:2111
 open_ctree+0x1245/0x2cf8 fs/btrfs/disk-io.c:3896
 btrfs_fill_super+0x1c7/0x2d0 fs/btrfs/super.c:1469
 btrfs_mount_root+0x803/0x930 fs/btrfs/super.c:1835
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 fc_mount fs/namespace.c:1043 [inline]
 vfs_kern_mount+0xb8/0x150 fs/namespace.c:1073
 btrfs_mount+0x39b/0xb40 fs/btrfs/super.c:1895
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
 do_mount fs/namespace.c:3399 [inline]
 __do_sys_mount fs/namespace.c:3607 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
 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: 0033:0x7fe91fd874ca
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe920c82e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe920c82ef0 RCX: 00007fe91fd874ca
RDX: 0000000020000000 RSI: 00000000200015c0 RDI: 00007fe920c82eb0
RBP: 0000000020000000 R08: 00007fe920c82ef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000200015c0
R13: 00007fe920c82eb0 R14: 000000000000559e R15: 0000000020001600
 </TASK>
rcu: rcu_preempt kthread starved for 10490 jiffies! g50961 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:26136 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 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:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 4409 Comm: kworker/u4:9 Not tainted 6.1.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0x1fae/0x3460 kernel/smp.c:998
Code: 2f 44 89 ee 83 e6 01 31 ff e8 0e 44 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 99 40 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff
RSP: 0018:ffffc900032275a0 EFLAGS: 00000293
RAX: ffffffff817f5b89 RBX: 1ffff110171c8595 RCX: ffff88802f525940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003227980 R08: ffffffff817f5b52 R09: fffffbfff2249e4d
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8e42ca8
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb4baca56c0 CR3: 000000000d08e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1334 [inline]
 text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534
 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:207
 static_key_enable+0x16/0x20 kernel/jump_label.c:220
 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/07 07:16 linux-6.1.y 7dc732d24ff7 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mount
2024/12/14 21:35 linux-6.1.y 52f863f820fd 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mount
* Struck through repros no longer work on HEAD.