syzbot


INFO: rcu detected stall in validate_mm

Status: upstream: reported syz repro on 2025/06/23 12:02
Reported-by: syzbot+05ef99915483f54c80eb@syzkaller.appspotmail.com
First crash: 1d17h, last: 1d17h
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in validate_mm (3) mm C error 35 20d 408d 0/29 upstream: reported C repro on 2024/05/12 09:19
upstream INFO: rcu detected stall in validate_mm (2) mm 2 596d 606d 0/29 auto-obsoleted due to no activity on 2024/02/04 15:00
linux-6.1 INFO: rcu detected stall in validate_mm (2) 7 18d 141d 0/3 upstream: reported on 2025/02/03 21:26
linux-6.1 INFO: rcu detected stall in validate_mm 6 259d 325d 0/3 auto-obsoleted due to no activity on 2025/01/16 23:39

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...0: (1 ticks this GP) idle=8e5/1/0x4000000000000000 softirq=7471/7471 fqs=2100 
	(detected by 1, t=10503 jiffies, g=9393, q=610)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4402 Comm: modprobe Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:kasan_check_range+0x1ab/0x290 mm/kasan/generic.c:-1
Code: 4d 89 d6 4d 8d 56 07 4d 85 f6 4d 0f 49 d6 49 83 e2 f8 4d 29 d6 74 12 41 80 39 00 0f 85 a0 00 00 00 49 ff c1 49 ff ce 75 ee 5b <41> 5e 41 5f c3 84 db 75 61 f7 c3 00 ff 00 00 75 5e f7 c3 00 00 ff
RSP: 0018:ffffc90000007888 EFLAGS: 00000056
RAX: 0000000000000001 RBX: ffff88801abebb80 RCX: ffffffff815c9cb4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ff9b0c8
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ff361a
R10: fffffbfff1ff361a R11: 1ffffffff1ff3619 R12: 0000000000000001
R13: dffffc0000000000 R14: 0000000000000001 R15: dffffc0000000001
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcafc54eec CR3: 0000000072ec4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 hlock_class kernel/locking/lockdep.c:197 [inline]
 mark_lock+0x94/0x320 kernel/locking/lockdep.c:4569
 mark_usage kernel/locking/lockdep.c:4483 [inline]
 __lock_acquire+0xc11/0x7c60 kernel/locking/lockdep.c:4966
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1694 [inline]
 __hrtimer_run_queues+0x5ff/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:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 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: 0018:ffffc9000361f9a0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 92af48d1c3fc0d00
RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff8a59a740
RBP: ffffc9000361fac0 R08: dffffc0000000000 R09: fffffbfff1ff3621
R10: fffffbfff1ff3621 R11: 1ffffffff1ff3620 R12: ffff888029ff77e8
R13: 1ffff920006c3f40 R14: 0000000000000246 R15: dffffc0000000000
 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
 anon_vma_lock_read include/linux/rmap.h:129 [inline]
 validate_mm+0x95/0x950 mm/mmap.c:403
 __mmap_region mm/mmap.c:1841 [inline]
 mmap_region+0x1231/0x15e0 mm/mmap.c:2921
 do_mmap+0x77a/0xdf0 mm/mmap.c:1574
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:551
 ksys_mmap_pgoff+0x542/0x780 mm/mmap.c:1623
 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: 0033:0x7f2741b9b242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007ffcafc54b48 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f2741ac5000 RCX: 00007f2741b9b242
RDX: 0000000000000005 RSI: 0000000000086000 RDI: 00007f2741ac5000
RBP: 0000000000000812 R08: 0000000000000000 R09: 0000000000010000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffcafc54b98
R13: 00007f2741b770c0 R14: 00007ffcafc54f50 R15: 00000fff95f8a96c
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/23 12:01 linux-5.15.y 1c700860e8bc d6cdfb8a .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in validate_mm
* Struck through repros no longer work on HEAD.