syzbot


INFO: rcu detected stall in shmem_fault (2)

Status: upstream: reported on 2024/06/03 20:13
Reported-by: syzbot+cf92cb07cc1063893ed7@syzkaller.appspotmail.com
First crash: 252d, last: 5d21h
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in shmem_fault (4) kernel 1 773d 773d 0/28 auto-obsoleted due to no activity on 2023/04/08 07:17
upstream INFO: rcu detected stall in shmem_fault mm 13 2156d 2316d 0/28 closed as dup on 2019/01/02 16:58
linux-6.1 INFO: rcu detected stall in shmem_fault 7 184d 249d 0/3 auto-obsoleted due to no activity on 2024/11/18 20:23
upstream INFO: rcu detected stall in shmem_fault (5) cgroups mm 3 543d 563d 23/28 fixed on 2023/10/12 12:48
linux-5.15 INFO: rcu detected stall in shmem_fault 1 528d 528d 0/3 auto-obsoleted due to no activity on 2023/12/11 11:17
upstream INFO: rcu detected stall in shmem_fault (3) fs mm 4 1022d 1022d 0/28 auto-closed as invalid on 2022/06/25 08:10
linux-6.1 INFO: rcu detected stall in shmem_fault (2) 2 28d 55d 0/3 upstream: reported on 2024/12/17 16:40
upstream INFO: rcu detected stall in shmem_fault (2) cgroups mm 1 1896d 1896d 0/28 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in shmem_fault (6) mm 78 1d00h 144d 0/28 upstream: reported on 2024/09/19 14:28

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=a07/1/0x4000000000000000 softirq=26158/26158 fqs=7 
	(detected by 0, t=10502 jiffies, g=36141, q=313)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9097 Comm: syz.6.1490 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:enqueue_hrtimer+0x155/0x390 kernel/time/hrtimer.c:1087
Code: d3 10 00 48 83 fd 1f 0f 87 05 01 00 00 e8 a3 cf 10 00 bb 01 00 00 00 89 e9 d3 e3 43 80 3c 27 00 74 08 4c 89 ef e8 eb b7 5a 00 <49> 8b 6d 00 48 83 c5 44 48 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0
RSP: 0018:ffffc90000dd0d28 EFLAGS: 00000046
RAX: ffffffff816fb5ed RBX: 0000000000000008 RCX: 0000000000000003
RDX: 0000000000010000 RSI: 0000000000000003 RDI: 0000000000000020
RBP: 0000000000000003 R08: ffffffff816fb5de R09: fffffbfff1c150ee
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880b8f2a400 R14: ffff88801a1b6340 R15: 1ffff110171e5480
FS:  00007f67075e56c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f68ac8debac CR3: 000000007d6e7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:1705 [inline]
 __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [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+0xac4/0x1fa0 arch/x86/kernel/unwind_orc.c:539
Code: c1 e8 03 80 3c 10 00 74 0f e8 58 ba 91 00 48 ba 00 00 00 00 00 fc ff df 48 89 5c 24 58 49 8b 6f 10 48 8b 44 24 38 0f b6 04 10 <84> c0 0f 85 80 0f 00 00 48 8b 04 24 48 8d 58 f8 41 83 3f 00 74 18
RSP: 0018:ffffc90002f2e928 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8e8b4ff7 RCX: ffffffff8e1f48e0
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffc90002f2e9f0
RBP: ffffc90002f30000 R08: 0000000000000001 R09: ffffc90002f2ead0
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1d169fe
R13: 1ffffffff1d169fe R14: ffffc90002f28000 R15: ffffc90002f2e9e0
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 save_stack+0xf6/0x1e0 mm/page_owner.c:119
 __set_page_owner+0x37/0x300 mm/page_owner.c:181
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465
 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146
 shmem_alloc_page mm/shmem.c:1586 [inline]
 shmem_alloc_and_acct_page+0x4d1/0xd10 mm/shmem.c:1611
 shmem_getpage_gfp+0x17b1/0x3190 mm/shmem.c:1906
 shmem_fault+0x1d7/0x700 mm/shmem.c:2118
 __do_fault+0x139/0x340 mm/memory.c:3926
 do_read_fault mm/memory.c:4262 [inline]
 do_fault mm/memory.c:4390 [inline]
 handle_pte_fault mm/memory.c:4648 [inline]
 __handle_mm_fault mm/memory.c:4783 [inline]
 handle_mm_fault+0x376f/0x5960 mm/memory.c:4881
 faultin_page mm/gup.c:976 [inline]
 __get_user_pages+0x4ed/0x11d0 mm/gup.c:1197
 populate_vma_page_range+0x215/0x2a0 mm/gup.c:1529
 __mm_populate+0x2a5/0x4a0 mm/gup.c:1638
 mm_populate include/linux/mm.h:2632 [inline]
 vm_mmap_pgoff+0x22b/0x2d0 mm/util.c:556
 ksys_mmap_pgoff+0x13e/0x780 mm/mmap.c:1623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f670977bde9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f67075e5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f6709994fa0 RCX: 00007f670977bde9
RDX: b635773f07ebbeeb RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f67097fd2a0 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f6709994fa0 R15: 00007fffaecbfca8
 </TASK>
rcu: rcu_preempt kthread starved for 10488 jiffies! g36141 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:26168 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 8966 Comm: syz.2.1436 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xa93/0xd90 kernel/smp.c:969
Code: 04 03 84 c0 0f 85 84 00 00 00 45 8b 7d 00 44 89 fe 83 e6 01 31 ff e8 3c d6 0b 00 41 83 e7 01 75 07 e8 d1 d2 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00
RSP: 0000:ffffc90004a67720 EFLAGS: 00000293
RAX: ffffffff8174b2e4 RBX: 1ffff110171e80b1 RCX: ffff88802bd6d940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004a67850 R08: ffffffff8174b2b4 R09: fffffbfff2131836
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: ffff8880b8f40588 R14: ffff8880b8e3b380 R15: 0000000000000001
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135
 invalidate_bdev+0x8a/0xb0 block/bdev.c:86
 ext4_put_super+0x8e9/0x1060 fs/ext4/super.c:1255
 generic_shutdown_super+0x130/0x310 fs/super.c:475
 kill_block_super+0x7a/0xe0 fs/super.c:1427
 deactivate_locked_super+0xa0/0x110 fs/super.c:335
 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x6a3/0x2480 kernel/exit.c:874
 do_group_exit+0x144/0x310 kernel/exit.c:996
 get_signal+0xc66/0x14e0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:280
RIP: 0033:0x7f5c5ee6bde9
Code: Unable to access opcode bytes at RIP 0x7f5c5ee6bdbf.
RSP: 002b:00007f5c5ccd4fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: 0000000000000000 RBX: 00007f5c5f084fa0 RCX: 00007f5c5ee6bde9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f5c5eeed2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f5c5f084fa0 R15: 00007fffb42ee398
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/05 16:19 linux-5.15.y c16c81c81336 4dc70884 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2024/12/02 17:59 linux-5.15.y 0a51d2d4527b b499ea68 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2024/10/27 20:55 linux-5.15.y 74cdd62cb470 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2024/09/30 06:12 linux-5.15.y 3a5928702e71 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2024/08/23 10:59 linux-5.15.y fa93fa65db6e ce8a9099 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2024/07/12 21:11 linux-5.15.y f45bea23c39c eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2024/06/03 20:12 linux-5.15.y c61bd26ae81a 0aba2352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2024/09/19 06:48 linux-5.15.y 3a5928702e71 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: rcu detected stall in shmem_fault
* Struck through repros no longer work on HEAD.