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INFO: rcu detected stall in sys_munmap

Status: auto-obsoleted due to no activity on 2025/10/24 12:55
Reported-by: syzbot+1bdbde0ecd9aae5086c3@syzkaller.appspotmail.com
First crash: 334d, last: 334d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in sys_munmap 1 7 166d 338d 0/2 auto-obsoleted due to no activity on 2026/04/09 22:56
upstream INFO: rcu detected stall in sys_munmap mm kasan 1 1 1012d 1012d 0/29 auto-obsoleted due to no activity on 2023/11/06 05:09
linux-6.1 INFO: rcu detected stall in sys_munmap (2) origin:upstream 1 C error 25 6d20h 439d 0/3 upstream: reported C repro on 2025/04/02 07:15
upstream INFO: rcu detected stall in sys_munmap (2) mm prio:low 1 C error error 44 9d10h 297d 0/29 upstream: reported C repro on 2025/08/22 04:15
linux-6.1 INFO: rcu detected stall in sys_munmap 1 1 692d 692d 0/3 auto-obsoleted due to no activity on 2024/10/31 01:03
linux-6.6 INFO: rcu detected stall in sys_munmap (2) 1 1 35d 35d 0/2 upstream: reported on 2026/05/11 10:40

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=f93/1/0x4000000000000000 softirq=39517/39518 fqs=39 
	(detected by 0, t=10502 jiffies, g=56101, q=10)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 11875 Comm: syz.5.1504 Not tainted 5.15.188-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline]
RIP: 0010:trace_hrtimer_expire_entry include/trace/events/timer.h:236 [inline]
RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1687 [inline]
RIP: 0010:__hrtimer_run_queues+0x441/0xc40 kernel/time/hrtimer.c:1754
Code: 03 42 80 3c 38 00 74 08 4c 89 f7 e8 49 98 55 00 49 8b 06 48 89 44 24 60 48 8b 7c 24 40 48 8b b4 24 b8 00 00 00 e8 ff 56 4b 08 <0f> 1f 44 00 00 e8 25 1f 10 00 65 44 8b 35 55 61 9a 7e bf 07 00 00
RSP: 0018:ffffc90000dd0d20 EFLAGS: 00000046
RAX: 1d3b714ad6cda100 RBX: 00000000fffffffd RCX: 0000000000010000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: ffffc90000dd0e98 R08: dffffc0000000000 R09: ffffed1017225441
R10: ffffed1017225441 R11: 1ffff11017225440 R12: ffff8880b912a310
R13: 1ffff11017225462 R14: ffff888064de2368 R15: dffffc0000000000
FS:  00007f64264df6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003c80 CR3: 000000007b761000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 3a810b1eb6134bdc DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 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:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:226 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x4/0x80 kernel/kcov.c:300
Code: 77 22 89 ff 89 f6 4a c7 44 02 08 05 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 <65> 48 8b 0d b4 98 8a 7e 65 8b 15 b5 98 8a 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900034af9a0 EFLAGS: 00000246
RAX: ffffffff81ac7f2a RBX: 00007f641e851000 RCX: ffff88802cd75940
RDX: 0000000000000002 RSI: 0000000000000200 RDI: 0000000000000000
RBP: ffffc900034afb01 R08: dffffc0000000000 R09: ffffed10059aeb29
R10: ffffed10059aeb29 R11: 1ffff110059aeb28 R12: 000000000000edb7
R13: ffffc900034afce0 R14: 800000000edb7225 R15: ffff8880612ad630
 vm_normal_page+0x6a/0x1e0 mm/memory.c:611
 zap_pte_range mm/memory.c:1357 [inline]
 zap_pmd_range mm/memory.c:1505 [inline]
 zap_pud_range mm/memory.c:1534 [inline]
 zap_p4d_range mm/memory.c:1555 [inline]
 unmap_page_range+0xa95/0x2520 mm/memory.c:1576
 unmap_vmas+0x11b/0x230 mm/memory.c:1653
 unmap_region+0x202/0x360 mm/mmap.c:2646
 __do_munmap+0x9d3/0xdc0 mm/mmap.c:2895
 __vm_munmap+0x137/0x230 mm/mmap.c:2948
 __do_sys_munmap mm/mmap.c:2974 [inline]
 __se_sys_munmap mm/mmap.c:2970 [inline]
 __x64_sys_munmap+0x67/0x70 mm/mmap.c:2970
 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: 0033:0x7f64286779b7
Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 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:00007f64264dee18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007f64286779b7
RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007f641e0bf000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005568
R10: 00000000000003c8 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f64264deef0 R14: 00007f64264deeb0 R15: 00007f641e0bf000
 </TASK>
rcu: rcu_preempt kthread starved for 10411 jiffies! g56101 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:27008 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 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:
NMI backtrace for cpu 0
CPU: 0 PID: 6070 Comm: kworker/0:19 Not tainted 5.15.188-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events bpf_prog_free_deferred
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 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:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 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:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:206
Code: 94 9c 8a 7e 65 8b 15 95 9c 8a 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 <83> fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14
RSP: 0018:ffffc9000358f838 EFLAGS: 00000246
RAX: ffffffff816c810b RBX: 0000000000000001 RCX: ffff88802be1d940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000358f980 R08: dffffc0000000000 R09: fffffbfff1ff761a
R10: fffffbfff1ff761a R11: 1ffffffff1ff7619 R12: ffff8880b9140588
R13: 1ffff110172280b1 R14: ffff8880b903b380 R15: 0000000000000001
 csd_lock_wait kernel/smp.c:440 [inline]
 smp_call_function_many_cond+0xbab/0xd70 kernel/smp.c:969
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135
 __purge_vmap_area_lazy+0x216/0x18f0 mm/vmalloc.c:1683
 _vm_unmap_aliases+0x410/0x4a0 mm/vmalloc.c:2107
 vm_remove_mappings mm/vmalloc.c:2584 [inline]
 __vunmap+0x70d/0xa40 mm/vmalloc.c:2611
 bpf_jit_binary_free kernel/bpf/core.c:918 [inline]
 bpf_jit_free+0x92/0x180 kernel/bpf/core.c:931
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/16 12:54 linux-5.15.y 89950c454265 124ec9cc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_munmap
* Struck through repros no longer work on HEAD.