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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: 140d, last: 4d20h
▶ ▼ 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 1120d 1171d 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 2221d 2220d 0/29 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in sys_mprotect (2) mm 1 1 2221d 2221d 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 38d 54d 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 97 5d05h 483d 0/29 upstream: reported syz repro on 2024/10/11 07:05
linux-5.15 INFO: rcu detected stall in sys_mprotect 1 1 650d 650d 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 175d 175d 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 1439d 1439d 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 100d 100d 0/3 auto-obsoleted due to no activity on 2026/02/05 12:28
upstream INFO: rcu detected stall in sys_mprotect (4) mm 1 1 1504d 1504d 0/29 closed as invalid on 2022/02/08 10:00
upstream INFO: rcu detected stall in sys_mprotect mm 1 3 2257d 2257d 0/29 closed as invalid on 2019/12/04 14:04
linux-5.15 INFO: rcu detected stall in sys_mprotect (2) 1 1 204d 204d 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 751d 979d 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 376d 376d 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 547d 623d 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 618d 618d 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): P12887/1:b..l
	(detected by 0, t=10502 jiffies, g=60305, q=160 ncpus=2)
task:rm              state:R  running task     stack:24336 pid:12887 ppid:12850  flags:0x00004002
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:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x4/0x80 kernel/kcov.c:313
Code: 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 03 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 90 48 8b 04 24 <65> 48 8b 15 64 f9 7f 7e 65 8b 0d 65 f9 7f 7e 81 e1 00 01 ff 00 74
RSP: 0018:ffffc9000c7af5f8 EFLAGS: 00000202
RAX: ffffffff8a19dde3 RBX: 00007f0119c34fff RCX: ffff88802aa5d940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003
RBP: ffffc9000c7af7b0 R08: ffff88802aa5d940 R09: 0000000000000004
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000008 R15: ffff888067b1f400
 ma_slots lib/maple_tree.c:795 [inline]
 mas_get_slot lib/maple_tree.c:6680 [inline]
 mas_validate_gaps lib/maple_tree.c:-1 [inline]
 mt_validate+0x2b53/0x4cb0 lib/maple_tree.c:7246
 validate_mm_mt+0xe2/0x440 mm/mmap.c:295
 validate_mm+0xe1/0x2e0 mm/mmap.c:332
 __vma_adjust+0x1855/0x1cd0 mm/mmap.c:879
 vma_adjust include/linux/mm.h:2810 [inline]
 __split_vma+0x3a7/0x500 mm/mmap.c:-1
 mprotect_fixup+0x5b1/0x800 mm/mprotect.c:608
 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: 0033:0x7f0119efc2c7
RSP: 002b:00007ffe28b55128 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007f0119ed8b20 RCX: 00007f0119efc2c7
RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007f0119c34000
RBP: 00007ffe28b553f0 R08: 0000000000000000 R09: 00007f0119c6e2e0
R10: 00007f0119ed8b20 R11: 0000000000000206 R12: 0000000000000018
R13: 000001be590c467e R14: 0000000000000000 R15: 00007f0119f10310
 </TASK>
rcu: rcu_preempt kthread starved for 10516 jiffies! g60305 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:27184 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12892 Comm: syz.9.1884 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:kasan_check_range+0x1b0/0x290 mm/kasan/generic.c:-1
Code: f3 4d 01 f3 49 89 df 49 8d 5f 07 4d 85 ff 49 0f 49 df 48 83 e3 f8 49 29 df 74 0e 41 80 3b 00 75 69 49 ff c3 49 ff cf 75 f2 5b <41> 5c 41 5e 41 5f 5d c3 45 84 ff 0f 85 91 00 00 00 41 f7 c7 00 ff
RSP: 0018:ffffc9000c8a7658 EFLAGS: 00000056
RAX: 0000000000000001 RBX: ffff88806578bb80 RCX: ffffffff8164fb44
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90af3270
RBP: 0000000000000003 R08: ffffffff90af3277 R09: 1ffffffff215e64e
R10: dffffc0000000000 R11: fffffbfff215e64f R12: dffffc0000000001
R13: dffffc0000000000 R14: 1ffffffff215e64e R15: 0000000000000001
FS:  00007f424af796c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000007d708000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 hlock_class kernel/locking/lockdep.c:228 [inline]
 mark_lock+0x94/0x320 kernel/locking/lockdep.c:4606
 mark_usage kernel/locking/lockdep.c:4529 [inline]
 __lock_acquire+0xcc1/0x7d10 kernel/locking/lockdep.c:5003
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
 __might_fault+0xc2/0x120 mm/memory.c:5850
 __clear_user arch/x86/include/asm/uaccess_64.h:96 [inline]
 copy_fpstate_to_sigframe+0x1bc/0xd50 arch/x86/kernel/fpu/signal.c:216
 get_sigframe arch/x86/kernel/signal.c:297 [inline]
 __setup_rt_frame arch/x86/kernel/signal.c:472 [inline]
 setup_rt_frame arch/x86/kernel/signal.c:784 [inline]
 handle_signal arch/x86/kernel/signal.c:828 [inline]
 arch_do_signal_or_restart+0x69f/0x1350 arch/x86/kernel/signal.c:873
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f424a19aeb7
Code: 83 c8 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
RSP: 002b:00007f424af790e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f424a415fa8 RCX: 00007f424a19aeb9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f424a415fa8
RBP: 00007f424a415fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f424a416038 R14: 00007ffdacb1fa90 R15: 00007ffdacb1fb78
 </TASK>

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/01 15:01 linux-6.1.y cd9b81672742 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_mprotect
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.