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INFO: rcu detected stall in sys_munmap

Status: upstream: reported on 2025/07/12 12:20
Reported-by: syzbot+9358c7457a4eb85a257e@syzkaller.appspotmail.com
First crash: 160d, last: 1d10h
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_munmap kasan mm 1 1 834d 834d 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 156d 156d 0/3 auto-obsoleted due to no activity on 2025/10/24 12:55
linux-6.1 INFO: rcu detected stall in sys_munmap (2) 1 17 9h05m 261d 0/3 upstream: reported on 2025/04/02 07:15
upstream INFO: rcu detected stall in sys_munmap (2) mm 1 C error 35 2h16m 119d 0/29 upstream: reported C repro on 2025/08/22 04:15
linux-6.1 INFO: rcu detected stall in sys_munmap 1 1 514d 514d 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): P6097/1:b..l P5136/1:b..l P6055/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=12817, q=611 ncpus=2)
task:udevd           state:R  running task     stack:24968 pid:6055  ppid:5136   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
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 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc9000b6cee00 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: c53156d579577300
RDX: 0000000000000000 RSI: ffffffff8aaace60 RDI: ffffffff8afc6f80
RBP: ffffc9000b6cef20 R08: dffffc0000000000 R09: 1ffffffff21b28a0
R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: 1ffff920016d9dcc
R13: ffffffff8cd2ff20 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 page_ext_get+0x3e/0x2b0 mm/page_ext.c:508
 __set_page_owner+0x28/0x60 mm/page_owner.c:194
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2081
 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x1b7/0x2e0 mm/slub.c:3519
 mt_alloc_one lib/maple_tree.c:162 [inline]
 mas_alloc_nodes+0x2f8/0x8c0 lib/maple_tree.c:1267
 mas_node_count_gfp lib/maple_tree.c:1347 [inline]
 mas_node_count lib/maple_tree.c:1361 [inline]
 mas_wr_node_store lib/maple_tree.c:3945 [inline]
 mas_wr_modify+0x1b2a/0x2a10 lib/maple_tree.c:4231
 mas_store_gfp+0x23f/0x320 lib/maple_tree.c:5440
 vma_iter_clear_gfp mm/internal.h:1164 [inline]
 do_vmi_align_munmap+0xd01/0x1660 mm/mmap.c:2572
 do_vmi_munmap+0x252/0x2d0 mm/mmap.c:2660
 __vm_munmap+0x193/0x3c0 mm/mmap.c:2961
 __do_sys_munmap mm/mmap.c:2978 [inline]
 __se_sys_munmap mm/mmap.c:2975 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:2975
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2d4cf1e097
RSP: 002b:00007fff1918de18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 000056140617fb10 RCX: 00007f2d4cf1e097
RDX: 0000561406182378 RSI: 0000000000000200 RDI: 00007f2d4d5ed000
RBP: 000000000000000d R08: 0000561406183190 R09: 0000000000000003
R10: 0000000000000010 R11: 0000000000000246 R12: 00005614061730b0
R13: 00007f2d4d72139c R14: 0000000000001a00 R15: 0000000000000009
 </TASK>
task:udevd           state:R  running task     stack:25000 pid:5136  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfa/0x110 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x11f/0x190 kernel/sched/wait.c:213
 sock_def_readable+0x1e1/0x430 net/core/sock.c:3354
 __netlink_sendskb net/netlink/af_netlink.c:1266 [inline]
 netlink_sendskb+0x9b/0x130 net/netlink/af_netlink.c:1272
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2d4cea7407
RSP: 002b:00007fff19193260 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2d4d5fa880 RCX: 00007f2d4cea7407
RDX: 0000000000000000 RSI: 00007fff191932c0 RDI: 0000000000000004
RBP: 0000561406176d70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b7
R13: 00005614061659e0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
task:syz.0.64        state:R  running task     stack:27592 pid:6097  ppid:5768   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1523 [inline]
 zap_pmd_range mm/memory.c:1571 [inline]
 zap_pud_range mm/memory.c:1600 [inline]
 zap_p4d_range mm/memory.c:1621 [inline]
 unmap_page_range+0x236f/0x2fe0 mm/memory.c:1642
 unmap_vmas+0x25e/0x3a0 mm/memory.c:1732
 exit_mmap+0x200/0xb50 mm/mmap.c:3302
 __mmput+0x118/0x3c0 kernel/fork.c:1355
 exit_mm+0x1da/0x2c0 kernel/exit.c:569
 do_exit+0x88e/0x23c0 kernel/exit.c:870
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f10a358f749
RSP: 002b:00007f10a445b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f10a37e6098 RCX: 00007f10a358f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f10a37e6098
RBP: 00007f10a37e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f10a37e6128 R14: 00007ffcf14be6e0 R15: 00007ffcf14be7c8
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/18 11:39 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_munmap
2025/12/06 16:12 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_munmap
2025/10/04 19:31 linux-6.6.y f34f16e5c632 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_munmap
2025/09/10 07:49 linux-6.6.y fe9731e10004 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_munmap
2025/08/17 07:59 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_munmap
2025/07/12 12:20 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_munmap
* Struck through repros no longer work on HEAD.