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ID Workflow Result Correct Bug Created Started Finished Revision Error
644e3073-a037-46b9-86ba-bbb6332d8275 assessment-kcsan 💥 KCSAN: data-race in dont_mount / lookup_fast 2026/01/15 13:55 2026/01/15 13:55 2026/01/15 13:59 a9d6a79219801d2130df3b1a792c57f0e5428e9f failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "128" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/usr/local/google/home/dvyukov/syzkaller/agent/workdir/cache/build/ae22ff18a2bdd936aac7c711f799309c8ad3d8de" "bzImage" "compile_commands.json"]: exit status 2

Crash report:
==================================================================
BUG: KCSAN: data-race in dont_mount / lookup_fast

read-write to 0xffff888106ae8f00 of 4 bytes by task 3530 on cpu 0:
 dont_mount+0x27/0x40 include/linux/dcache.h:363
 vfs_unlink+0x298/0x430 fs/namei.c:4345
 do_unlinkat+0x236/0x4c0 fs/namei.c:4407
 __do_sys_unlink fs/namei.c:4455 [inline]
 __se_sys_unlink fs/namei.c:4453 [inline]
 __x64_sys_unlink+0x30/0x40 fs/namei.c:4453
 x64_sys_call+0x28a3/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888106ae8f00 of 4 bytes by task 2784 on cpu 1:
 d_revalidate fs/namei.c:860 [inline]
 lookup_fast+0xd9/0x2a0 fs/namei.c:1641
 walk_component+0x3f/0x230 fs/namei.c:2000
 lookup_last fs/namei.c:2469 [inline]
 path_lookupat+0x10a/0x2b0 fs/namei.c:2493
 filename_lookup+0x127/0x300 fs/namei.c:2522
 user_path_at_empty+0x42/0x120 fs/namei.c:2929
 do_readlinkat+0x92/0x210 fs/stat.c:499
 __do_sys_readlink fs/stat.c:532 [inline]
 __se_sys_readlink fs/stat.c:529 [inline]
 __x64_sys_readlink+0x47/0x60 fs/stat.c:529
 x64_sys_call+0x264b/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:90
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00600008 -> 0x00008008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2784 Comm: udevd Not tainted 6.10.0-rc2-syzkaller-00222-gd30d0e49da71 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================

Trajectory:
Seq Timestamp Type Name Duration
0/0 2026/01/15 13:55 flow assessment-kcsan
3m Model: 
unknown

Error: 
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "128" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/usr/local/google/home/dvyukov/syzkaller/agent/workdir/cache/build/ae22ff18a2bdd936aac7c711f799309c8ad3d8de" "bzImage" "compile_commands.json"]: exit status 2
1/1 2026/01/15 13:56 action kernel-checkouter
0m Model: 
unknown

Results: 
map[KernelSrc:/usr/local/google/home/dvyukov/syzkaller/agent/workdir/cache/src/cf516581c5e7ab349c52fa8f715699422dda9abc]
2/1 2026/01/15 13:56 action kernel-builder
2m Model: 
unknown

Error: 
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "128" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/usr/local/google/home/dvyukov/syzkaller/agent/workdir/cache/build/ae22ff18a2bdd936aac7c711f799309c8ad3d8de" "bzImage" "compile_commands.json"]: exit status 2

Results: 
map[KernelObj:]
LLM Calls Summary:
Total Calls Total Tokens Avg Tokens Total Duration (Seconds) Avg Duration (Seconds)
Tool Calls Summary:
Total Calls Total Duration (Seconds) Avg Duration (Seconds)