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INFO: rcu detected stall in sys_munmap (2)

Status: upstream: reported on 2025/04/02 07:15
Reported-by: syzbot+87c23d2143b7fa642291@syzkaller.appspotmail.com
First crash: 152d, last: 18d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in sys_munmap 1 2 15d 51d 0/2 upstream: reported on 2025/07/12 12:20
upstream INFO: rcu detected stall in sys_munmap kasan mm 1 1 725d 725d 0/29 auto-obsoleted due to no activity on 2023/11/06 05:09
linux-5.15 INFO: rcu detected stall in sys_munmap 1 1 47d 47d 0/3 upstream: reported on 2025/07/16 12:55
upstream INFO: rcu detected stall in sys_munmap (2) mm 1 syz 24 13d 10d 0/29 upstream: reported syz repro on 2025/08/22 04:15
linux-6.1 INFO: rcu detected stall in sys_munmap 1 1 405d 405d 0/3 auto-obsoleted due to no activity on 2024/10/31 01:03

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3637/1:b..l P6474/1:b..l P4451/1:b..l
	(detected by 0, t=10503 jiffies, g=33533, q=63 ncpus=2)
task:kworker/u4:8    state:R  running task     stack:20688 pid:4451  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 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 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0000:ffffc90004b5fac0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 09e357781b24ba00
RDX: 0000000000000000 RSI: ffffffff8a8c15e0 RDI: ffffffff8adef320
RBP: ffffc90004b5fbc8 R08: dffffc0000000000 R09: fffffbfff215ba49
R10: fffffbfff215ba49 R11: 1ffffffff215ba48 R12: 0000000000000001
R13: 1ffff9200096bf64 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xeb/0x600 net/batman-adv/network-coding.c:719
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
task:udevd           state:R  running task     stack:24928 pid:6474  ppid:3637   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:215
Code: 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 00 87 9e 0c 48 89 de 5b e9 87 53 4f 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d 54 a8 81 7e 65 8b 15 55 a8 81 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc9000c567718 EFLAGS: 00000246
RAX: ffffffff8a03ceb8 RBX: ffff888072738c00 RCX: ffff88802bb09dc0
RDX: 0000000000000000 RSI: ffff888072738c00 RDI: ffff888072738c00
RBP: ffffc9000c5678f0 R08: ffff88802bb09dc0 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888072738c00
R13: ffffffff8bb137a3 R14: 0000000000000004 R15: ffff88801e335600
 mas_validate_child_slot lib/maple_tree.c:7091 [inline]
 mt_validate+0x1628/0x4c90 lib/maple_tree.c:7241
 validate_mm_mt+0xcd/0x420 mm/mmap.c:294
 validate_mm+0xcc/0x2b0 mm/mmap.c:331
 remove_mt mm/mmap.c:2318 [inline]
 do_mas_align_munmap+0xf98/0x1220 mm/mmap.c:2591
 do_mas_munmap+0x240/0x2b0 mm/mmap.c:2646
 __vm_munmap+0x18d/0x290 mm/mmap.c:2932
 __do_sys_munmap mm/mmap.c:2957 [inline]
 __se_sys_munmap mm/mmap.c:2954 [inline]
 __x64_sys_munmap+0x5c/0x70 mm/mmap.c:2954
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f43c2b1e097
RSP: 002b:00007fffa959c418 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00005558ddf9b1a0 RCX: 00007f43c2b1e097
RDX: 00005558ddf98418 RSI: 0000000000000200 RDI: 00007f43c3185000
RBP: 0000000000000001 R08: 00005558ddfaf9b0 R09: 00005558ddf9d630
R10: 0000000000000010 R11: 0000000000000246 R12: 00005558ddf970c0
R13: 00007f43c32ad39c R14: 0000000000000200 R15: 0000000000000009
 </TASK>
task:udevd           state:R  running task     stack:22624 pid:3637  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:215
Code: 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 00 87 9e 0c 48 89 de 5b e9 87 53 4f 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d 54 a8 81 7e 65 8b 15 55 a8 81 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90003317908 EFLAGS: 00000202
RAX: ffffffff81ec8928 RBX: 0000000000000001 RCX: 26559abbc34bc100
RDX: ffff88807c63bb80 RSI: ffffffff8adef300 RDI: ffffffff8adef2c0
RBP: 0000000000000ffd R08: dffffc0000000000 R09: fffffbfff215ba49
R10: fffffbfff215ba49 R11: 1ffffffff215ba48 R12: dffffc0000000000
R13: ffff88806ff50540 R14: ffff88807351cffd R15: 0000000000000ffe
 rcu_read_lock include/linux/rcupdate.h:792 [inline]
 prepend_path+0x78/0xc20 fs/d_path.c:163
 d_absolute_path+0x9e/0x140 fs/d_path.c:233
 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline]
 tomoyo_realpath_from_path+0x2d5/0x5d0 security/tomoyo/realpath.c:271
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x1fd/0x550 security/tomoyo/file.c:822
 security_inode_getattr+0xcf/0x120 security/security.c:1361
 vfs_getattr+0x26/0x3a0 fs/stat.c:158
 vfs_fstat fs/stat.c:183 [inline]
 __do_sys_newfstat fs/stat.c:447 [inline]
 __se_sys_newfstat fs/stat.c:444 [inline]
 __x64_sys_newfstat+0x102/0x1c0 fs/stat.c:444
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f43c2b11ad7
RSP: 002b:00007fffa95a1848 EFLAGS: 00000206 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f43c2b11ad7
RDX: 0000000000090800 RSI: 00007fffa95a1850 RDI: 000000000000000d
RBP: 00007fffa95a1850 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 00005558ddfa47c0
R13: 00000000000000ff R14: 00005558d90b7be0 R15: 00007fffa95a1b70
 </TASK>
rcu: rcu_preempt kthread starved for 10570 jiffies! g33533 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:27840 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4356 Comm: kworker/u4:6 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0xe7b/0x1270 kernel/smp.c:998
Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 5d d9 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 e9 d5 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 ce d5 0a
RSP: 0018:ffffc90004797800 EFLAGS: 00000293
RAX: ffffffff8175f112 RBX: dffffc0000000000 RCX: ffff888024ac1dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004797960 R08: dffffc0000000000 R09: fffffbfff215ba49
R10: fffffbfff215ba49 R11: 1ffffffff215ba48 R12: 1ffff110171c85ad
R13: ffff8880b8f3bb40 R14: 0000000000000000 R15: ffff8880b8e42d68
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2dc62b CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <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:1574 [inline]
 text_poke_bp_batch+0x2b0/0x7d0 arch/x86/kernel/alternative.c:1774
 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207
 static_key_enable+0x16/0x20 kernel/jump_label.c:220
 toggle_allocation_gate+0xb4/0x430 mm/kfence/core.c:805
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/14 02:50 linux-6.1.y 3594f306da12 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_munmap
2025/08/10 13:23 linux-6.1.y 3594f306da12 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_munmap
2025/06/18 09:05 linux-6.1.y 58485ff1a74f e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_munmap
2025/06/12 09:22 linux-6.1.y 58485ff1a74f 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_munmap
2025/06/01 10:10 linux-6.1.y da3c5173c55f 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_munmap
2025/04/02 07:16 linux-6.1.y 8e60a714ba3b c799dfdd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_munmap
2025/04/02 07:14 linux-6.1.y 8e60a714ba3b c799dfdd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_munmap
* Struck through repros no longer work on HEAD.