KCSAN: data-race in autofs_wait / autofs_wait

Status: moderation: reported C repro on 2026/04/27 07:55
Subsystems: autofs
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+c6d286fd51860df64d9a@syzkaller.appspotmail.com
First crash: 168d, last: 2d01h
▶ ▼ ✨ AI Jobs (4)
ID Workflow Result Correct Bug Created Started Finished Revision
f3cbda85 repro-c Reproduced: ✅ ❓ KCSAN: data-race in autofs_wait / autofs_wait 2026/10/10 16:25 2026/10/10 16:25 2026/10/10 17:11 4f92358f
60ba7df8 repro-c 💥 KCSAN: data-race in autofs_wait / autofs_wait 2026/10/08 16:11 2026/10/08 16:11 2026/10/08 16:42 723be09b
f6659d5c assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KCSAN: data-race in autofs_wait / autofs_wait 2026/05/20 07:35 2026/05/20 07:35 2026/05/20 08:09 0909d65f
10dd8583 assessment-kcsan Benign: ✅ Confident: ✅ ❓ KCSAN: data-race in autofs_wait / autofs_wait 2026/04/27 07:54 2026/04/27 07:54 2026/04/27 08:15 9c2d0995
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/10/10 18:56 15m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 3857c2fe5449541e24afc5efdb0f81a8a8f9a3a0 report job log log

Sample crash report:
==================================================================
BUG: KCSAN: data-race in autofs_wait / autofs_wait

read to 0xffffffff870034e0 of 4 bytes by task 4650 on cpu 1:
 autofs_wait+0x8b1/0xbd0 fs/autofs/waitq.c:386
 autofs_mount_wait+0xc2/0x100 fs/autofs/root.c:256
 autofs_d_automount+0x3fd/0x570 fs/autofs/root.c:410
 follow_automount fs/namei.c:1565 [inline]
 __traverse_mounts+0x256/0x420 fs/namei.c:1618
 traverse_mounts fs/namei.c:1647 [inline]
 handle_mounts fs/namei.c:1749 [inline]
 step_into_slowpath+0x374/0x600 fs/namei.c:2131
 step_into fs/namei.c:2181 [inline]
 walk_component fs/namei.c:2317 [inline]
 lookup_last fs/namei.c:2818 [inline]
 path_lookupat+0x2eb/0x4c0 fs/namei.c:2842
 filename_lookup+0x18f/0x390 fs/namei.c:2871
 __do_sys_chdir fs/open.c:557 [inline]
 __se_sys_chdir+0x58/0x1f0 fs/open.c:550
 __x64_sys_chdir+0x1f/0x30 fs/open.c:550
 x64_sys_call+0x1e75/0x2550 arch/x86/include/generated/asm/syscalls_64.h:81
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffffffff870034e0 of 4 bytes by task 4651 on cpu 0:
 autofs_wait+0x8dc/0xbd0 fs/autofs/waitq.c:-1
 autofs_mount_wait+0xc2/0x100 fs/autofs/root.c:256
 autofs_d_automount+0x3fd/0x570 fs/autofs/root.c:410
 follow_automount fs/namei.c:1565 [inline]
 __traverse_mounts+0x256/0x420 fs/namei.c:1618
 traverse_mounts fs/namei.c:1647 [inline]
 handle_mounts fs/namei.c:1749 [inline]
 step_into_slowpath+0x374/0x600 fs/namei.c:2131
 step_into fs/namei.c:2181 [inline]
 walk_component fs/namei.c:2317 [inline]
 lookup_last fs/namei.c:2818 [inline]
 path_lookupat+0x2eb/0x4c0 fs/namei.c:2842
 filename_lookup+0x18f/0x390 fs/namei.c:2871
 __do_sys_chdir fs/open.c:557 [inline]
 __se_sys_chdir+0x58/0x1f0 fs/open.c:550
 __x64_sys_chdir+0x1f/0x30 fs/open.c:550
 x64_sys_call+0x1e75/0x2550 arch/x86/include/generated/asm/syscalls_64.h:81
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000003e1 -> 0x000003e2

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4651 Comm: syz-executor279 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================

Crashes (36):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/10 19:11 git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 3857c2fe5449 f7710056 .config console log report C ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/10/06 20:00 upstream 69f80fef3153 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/10/01 10:51 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/09/30 00:09 upstream 6f8319e3e9a4 328436b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/09/16 22:38 upstream 238650ef6c7c 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/09/14 10:35 upstream 704340f1cd0d 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/08/19 05:35 upstream bd5f485f3f02 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/08/15 08:09 upstream dac3e89a2c90 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/08/06 19:12 upstream fcaeecb8b0cd c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/31 15:23 upstream 8ba098e6b6ff 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/27 14:48 upstream f5098b6bae76 aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/18 13:04 upstream 94515f3a7d42 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/18 13:04 upstream 94515f3a7d42 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/17 07:50 upstream fce2dfa773ce 7f27c57a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/16 03:03 upstream 58717b2a1365 27a8bd60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/16 03:02 upstream 58717b2a1365 27a8bd60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/11 01:23 upstream d96fcfe1b7f9 99e64375 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/07/02 13:42 upstream 4a50a141f05a 27192279 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/06/26 23:47 upstream 51cb1aa1250c fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/06/25 10:12 upstream ab9de95c9cf9 cfa969bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/06/21 00:57 upstream 1a3746ccbb0a 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/06/21 00:56 upstream 1a3746ccbb0a 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/06/21 00:56 upstream 1a3746ccbb0a 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/06/07 01:34 upstream 8e65320d91cd cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/21 02:18 upstream 8bc67e4db64a 41b8c833 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/21 02:18 upstream 8bc67e4db64a 41b8c833 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/21 02:18 upstream 8bc67e4db64a 41b8c833 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/21 02:17 upstream 8bc67e4db64a 41b8c833 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/18 15:57 upstream 5200f5f493f7 55156e84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/18 15:56 upstream 5200f5f493f7 55156e84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/18 03:47 upstream e5d505e3664b de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/18 03:44 upstream e5d505e3664b de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/02 22:41 upstream 66edb901bf87 a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/02 22:40 upstream 66edb901bf87 a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/05/01 10:15 upstream 26fd6bff2c05 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
2026/04/27 07:54 upstream 20b64cf8705a 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in autofs_wait / autofs_wait
* Struck through repros no longer work on HEAD.