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KCSAN: data-race in do_fcntl / do_fcntl (2)

Status: moderation: reported on 2024/06/28 15:08
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+31c0e4d3406d4483bb8f@syzkaller.appspotmail.com
First crash: 14d, last: 14d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_fcntl / do_fcntl fs 3 153d 162d 0/27 auto-obsoleted due to no activity on 2024/03/16 15:54

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

write to 0xffff88810a1b336c of 4 bytes by task 8658 on cpu 1:
 do_fcntl+0x7a7/0xe20 fs/fcntl.c:432
 __do_sys_fcntl fs/fcntl.c:492 [inline]
 __se_sys_fcntl+0xc4/0x190 fs/fcntl.c:477
 __x64_sys_fcntl+0x43/0x50 fs/fcntl.c:477
 x64_sys_call+0x292f/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:73
 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

write to 0xffff88810a1b336c of 4 bytes by task 8654 on cpu 0:
 do_fcntl+0x7a7/0xe20 fs/fcntl.c:432
 __do_sys_fcntl fs/fcntl.c:492 [inline]
 __se_sys_fcntl+0xc4/0x190 fs/fcntl.c:477
 __x64_sys_fcntl+0x43/0x50 fs/fcntl.c:477
 x64_sys_call+0x292f/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:73
 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: 0x00000000 -> 0x00000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8654 Comm: syz.3.1239 Not tainted 6.10.0-rc5-syzkaller-00200-g5bbd9b249880 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/28 15:08 upstream 5bbd9b249880 757f06b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in do_fcntl / do_fcntl
* Struck through repros no longer work on HEAD.