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INFO: rcu detected stall in sys_mprotect (3)

Status: upstream: reported on 2025/09/19 07:33
Reported-by: syzbot+38389a646a23817e3097@syzkaller.appspotmail.com
First crash: 131d, last: 1d06h
▶ ▼ Similar bugs (16)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_mprotect (6) kernel 1 3 1112d 1163d 0/29 auto-obsoleted due to no activity on 2023/04/20 15:51
upstream INFO: rcu detected stall in sys_mprotect (3) mm 1 3 2212d 2212d 0/29 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in sys_mprotect (2) mm 1 1 2212d 2212d 0/29 closed as invalid on 2020/01/08 05:23
linux-6.6 INFO: rcu detected stall in sys_mprotect (2) origin:lts-only 1 syz error 3 29d 45d 0/2 upstream: reported syz repro on 2025/12/14 03:47
upstream INFO: rcu detected stall in sys_mprotect (8) mm 1 syz done 96 21d 474d 0/29 upstream: reported syz repro on 2024/10/11 07:05
linux-5.15 INFO: rcu detected stall in sys_mprotect 1 1 642d 642d 0/3 auto-obsoleted due to no activity on 2024/08/04 17:12
linux-6.6 INFO: rcu detected stall in sys_mprotect 1 1 167d 167d 0/2 auto-obsoleted due to no activity on 2025/11/23 01:57
upstream INFO: rcu detected stall in sys_mprotect (5) kernel 1 1 1431d 1431d 0/29 auto-closed as invalid on 2022/05/29 03:15
linux-5.15 INFO: rcu detected stall in sys_mprotect (3) 1 1 92d 92d 0/3 upstream: reported on 2025/10/28 12:28
upstream INFO: rcu detected stall in sys_mprotect (4) mm 1 1 1496d 1496d 0/29 closed as invalid on 2022/02/08 10:00
upstream INFO: rcu detected stall in sys_mprotect mm 1 3 2248d 2248d 0/29 closed as invalid on 2019/12/04 14:04
linux-5.15 INFO: rcu detected stall in sys_mprotect (2) 1 1 196d 196d 0/3 auto-obsoleted due to no activity on 2025/10/24 12:50
upstream INFO: rcu detected stall in sys_mprotect (7) mm 1 9 743d 970d 0/29 auto-obsoleted due to no activity on 2024/04/15 19:55
linux-6.1 INFO: rcu detected stall in sys_mprotect (2) 1 1 367d 367d 0/3 auto-obsoleted due to no activity on 2025/05/06 08:25
linux-6.1 INFO: rcu detected stall in sys_mprotect 1 7 538d 614d 0/3 auto-obsoleted due to no activity on 2024/11/16 09:36
android-5-15 BUG: soft lockup in sys_mprotect 1 1 609d 609d 0/2 auto-obsoleted due to no activity on 2024/08/27 08:23

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P10117/1:b..l P14865/1:b..l
	(detected by 1, t=10502 jiffies, g=92933, q=57 ncpus=2)
task:syz.4.2173      state:R  running task     stack:26480 pid:14865 ppid:12706  flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
 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:ma_dead_node lib/maple_tree.c:538 [inline]
RIP: 0010:mas_data_end lib/maple_tree.c:1489 [inline]
RIP: 0010:mt_validate_nulls lib/maple_tree.c:7200 [inline]
RIP: 0010:mt_validate+0x44f6/0x4cb0 lib/maple_tree.c:7249
Code: 00 e8 0e 7b 68 f7 49 8d 46 08 48 89 44 24 20 eb 0e e8 fe 7a 68 f7 48 c7 44 24 20 00 00 00 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 <74> 08 4c 89 f7 e8 d0 65 b9 f7 4d 8b 26 48 c7 c0 00 ff ff ff 49 21
RSP: 0018:ffffc900041778c0 EFLAGS: 00000246
RAX: 1ffff1100f4729c0 RBX: dffffc0000000000 RCX: ffff888078a20000
RDX: 0000000000000000 RSI: ffffffff8e08a3c0 RDI: 0000000000000001
RBP: ffffc90004177a70 R08: ffff888078a20000 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffff8880740a5b60
R13: ffff88807a394e80 R14: ffff88807a394e00 R15: 0000000000000001
 validate_mm_mt+0xe2/0x440 mm/mmap.c:295
 __split_vma+0x30/0x500 mm/mmap.c:2355
 mprotect_fixup+0x502/0x800 mm/mprotect.c:602
 do_mprotect_pkey+0x7fe/0xba0 mm/mprotect.c:777
 __do_sys_mprotect mm/mprotect.c:804 [inline]
 __se_sys_mprotect mm/mprotect.c:801 [inline]
 __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:801
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5c6c19acb7
RSP: 002b:00007ffff8baadb8 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007f5c6cfa46c0 RCX: 00007f5c6c19acb7
RDX: 0000000000000003 RSI: 0000000000020000 RDI: 00007f5c6cf85000
RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000021000 R11: 0000000000000206 R12: 00007ffff8baaf10
R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000
 </TASK>
task:syz-executor    state:R  running task     stack:21520 pid:10117 ppid:10108  flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6731
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6755
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 unwind_next_frame+0x1892/0x20b0 arch/x86/kernel/unwind_orc.c:629
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 save_stack+0x121/0x230 mm/page_owner.c:127
 __reset_page_owner+0x51/0x1a0 mm/page_owner.c:148
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
 release_pages+0x1fa6/0x2220 mm/swap.c:1035
 __pagevec_release+0x6d/0xe0 mm/swap.c:1055
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x7c2/0x20c0 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x25b/0xa80 mm/shmem.c:1171
 evict+0x4c9/0x8d0 fs/inode.c:705
 do_unlinkat+0x388/0x580 fs/namei.c:4405
 __do_sys_unlink fs/namei.c:4446 [inline]
 __se_sys_unlink fs/namei.c:4444 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4444
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f855e599fa7
RSP: 002b:00007ffc86fef878 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f855e599fa7
RDX: 00007ffc86fef8a0 RSI: 00007ffc86fef930 RDI: 00007ffc86fef930
RBP: 00007ffc86fef930 R08: 00007ffc86ff0930 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc86ff09c0
R13: 00007f855e60471f R14: 00000000001258f0 R15: 00007ffc86ff0a00
 </TASK>
rcu: rcu_preempt kthread starved for 10566 jiffies! g92933 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:26864 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 schedule+0xb9/0x180 kernel/sched/core.c:6638
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 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:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 a7 10 9d f7 e9 44 ff ff ff e8 7d 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 87 5d 50 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc90000177de8 EFLAGS: 000002c6
RAX: 31c14cb3c4055600 RBX: ffffffff8a3651a7 RCX: 31c14cb3c4055600
RDX: 0000000000000001 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0c20
RBP: ffffc90000177f20 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 1ffff9200002efc8
R13: dffffc0000000000 R14: ffff888017739dc0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c38dc80 CR3: 0000000028932000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x20d/0x5a0 kernel/sched/idle.c:303
 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401
 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/27 20:57 linux-6.1.y cd9b81672742 9a514c2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mprotect
2026/01/25 09:09 linux-6.1.y cd9b81672742 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_mprotect
2025/12/06 06:40 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mprotect
2025/10/17 18:09 linux-6.1.y c2fda4b3f577 7adf5298 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mprotect
2025/10/12 23:57 linux-6.1.y 882efbdd9d34 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mprotect
2025/09/30 14:18 linux-6.1.y 7b34dc04e4ff 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mprotect
2025/09/25 09:14 linux-6.1.y 363a599da6d9 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mprotect
2025/09/19 07:32 linux-6.1.y 3db754f56897 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mprotect
* Struck through repros no longer work on HEAD.