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: 827d, last: 7d17h
Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in shmem_fault (4) kernel 1 1 1347d 1347d 0/29 auto-obsoleted due to no activity on 2023/04/08 07:17
upstream INFO: rcu detected stall in shmem_fault mm 1 13 2731d 2891d 0/29 closed as dup on 2019/01/02 16:58
linux-6.6 INFO: rcu detected stall in shmem_fault 1 9 196d 449d 0/2 auto-obsoleted due to no activity on 2026/06/04 20:40
linux-6.1 INFO: rcu detected stall in shmem_fault 1 7 759d 823d 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 1 3 1118d 1138d 23/29 fixed on 2023/10/12 12:48
linux-5.15 INFO: rcu detected stall in shmem_fault 1 1 1102d 1102d 0/3 auto-obsoleted due to no activity on 2023/12/11 11:17
upstream INFO: rcu detected stall in shmem_fault (3) mm fs 1 4 1596d 1597d 0/29 auto-closed as invalid on 2022/06/25 08:10
linux-6.1 INFO: rcu detected stall in shmem_fault (2) 1 22 114d 630d 0/3 auto-obsoleted due to no activity on 2026/08/25 07:39
upstream INFO: rcu detected stall in shmem_fault (2) cgroups mm 1 1 2470d 2470d 0/29 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in shmem_fault (6) mm prio:low 1 syz, C 264 5d12h 719d 0/29 upstream: reported C repro on 2024/09/19 14:28
upstream BUG: workqueue lockup (5) prio:low kernel 1 syz, C done 17764 37m 2429d 0/29 upstream: reported C repro on 2020/01/14 22:04

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=40f/1/0x4000000000000000 softirq=28278/28279 fqs=399 
	(t=10502 jiffies g=40169 q=397)
rcu: rcu_preempt kthread starved for 9705 jiffies! g40169 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:26896 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
 kthread+0x42e/0x520 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729
NMI backtrace for cpu 1
CPU: 1 PID: 11120 Comm: syz.5.1975 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22d/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31f/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ec/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 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:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90002f7e920 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 91b2f9016c569100
RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a43c0
RBP: ffffc90002f7ea28 R08: dffffc0000000000 R09: 1ffffffff203de18
R10: dffffc0000000000 R11: fffffbfff203de19 R12: ffffffff8c3bc2d0
R13: 1ffff920005efd30 R14: 0000000000000246 R15: dffffc0000000000
 down_read_trylock+0x22e/0x3b0 kernel/locking/rwsem.c:1540
 shrink_slab_memcg mm/vmscan.c:807 [inline]
 shrink_slab+0x228/0x7a0 mm/vmscan.c:913
 shrink_node_memcgs mm/vmscan.c:2958 [inline]
 shrink_node+0x11f5/0x2790 mm/vmscan.c:3079
 shrink_zones mm/vmscan.c:3285 [inline]
 do_try_to_free_pages+0x60e/0x1600 mm/vmscan.c:3340
 try_to_free_mem_cgroup_pages+0x347/0x800 mm/vmscan.c:3654
 try_charge_memcg+0x42f/0x15b0 mm/memcontrol.c:2654
 try_charge mm/memcontrol.c:2779 [inline]
 charge_memcg+0x100/0x300 mm/memcontrol.c:6765
 __mem_cgroup_charge+0x21/0x80 mm/memcontrol.c:6801
 mem_cgroup_charge include/linux/memcontrol.h:700 [inline]
 shmem_add_to_page_cache+0xa8a/0x14d0 mm/shmem.c:718
 shmem_getpage_gfp+0x1735/0x2c10 mm/shmem.c:1940
 shmem_fault+0x1ac/0x550 mm/shmem.c:2118
 __do_fault+0x141/0x330 mm/memory.c:3928
 do_read_fault mm/memory.c:4264 [inline]
 do_fault mm/memory.c:4392 [inline]
 handle_pte_fault mm/memory.c:4650 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x2982/0x4440 mm/memory.c:4883
 faultin_page mm/gup.c:976 [inline]
 __get_user_pages+0x952/0x11e0 mm/gup.c:1197
 populate_vma_page_range+0x213/0x290 mm/gup.c:1529
 __mm_populate+0x275/0x3b0 mm/gup.c:1638
 mm_populate include/linux/mm.h:2646 [inline]
 vm_mmap_pgoff+0x212/0x2d0 mm/util.c:556
 ksys_mmap_pgoff+0x140/0x790 mm/mmap.c:1635
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5d47ffc159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5d46254028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f5d48283fa0 RCX: 00007f5d47ffc159
RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f5d48093024 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5d48284038 R14: 00007f5d48283fa0 R15: 00007fffec1ae1a8
 </TASK>

Crashes (28):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/01 08:26 linux-5.15.y 28c35638ec51 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2026/07/29 09:23 linux-5.15.y 674f684f7c61 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2026/07/15 13:06 linux-5.15.y c86c4726e7f0 a4ed0f4f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2026/06/03 04:58 linux-5.15.y dc027a595035 3c0d2131 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2026/05/18 06:42 linux-5.15.y 93741761e5e3 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2026/02/24 06:41 linux-5.15.y 3330a8d33e08 41d2fa6a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/12/10 17:37 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/11/28 11:55 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/11/26 22:49 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/10/03 21:06 linux-5.15.y 29e53a5b1c4f 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/08/18 08:43 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/08/08 03:41 linux-5.15.y c79648372d02 6a893178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/07/07 05:08 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/06/26 08:03 linux-5.15.y 1c700860e8bc 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/06/24 16:43 linux-5.15.y 1c700860e8bc e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/06/24 16:38 linux-5.15.y 1c700860e8bc e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/06/22 16:16 linux-5.15.y 1c700860e8bc d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/05/25 09:01 linux-5.15.y 98f47d0e9b8c ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/05/19 05:37 linux-5.15.y a68c15152131 f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
2025/02/14 06:45 linux-5.15.y c16c81c81336 d9a046cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in shmem_fault
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.