syzbot


KCSAN: data-race in do_fcntl / do_fcntl

Status: auto-obsoleted due to no activity on 2024/03/16 15:54
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+2fb2065ce74d09b92949@syzkaller.appspotmail.com
First crash: 77d, last: 68d

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

write to 0xffff8881314a3d6c of 4 bytes by task 25632 on cpu 1:
 do_fcntl+0x777/0xeb0 fs/fcntl.c:399
 __do_sys_fcntl fs/fcntl.c:456 [inline]
 __se_sys_fcntl+0xc4/0x180 fs/fcntl.c:441
 __x64_sys_fcntl+0x43/0x50 fs/fcntl.c:441
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

write to 0xffff8881314a3d6c of 4 bytes by task 25633 on cpu 0:
 do_fcntl+0x777/0xeb0 fs/fcntl.c:399
 __do_sys_fcntl fs/fcntl.c:456 [inline]
 __se_sys_fcntl+0xc4/0x180 fs/fcntl.c:441
 __x64_sys_fcntl+0x43/0x50 fs/fcntl.c:441
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000 -> 0x00000012

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25633 Comm: syz-executor.4 Tainted: G        W          6.8.0-rc3-syzkaller-00279-g4a7bbe7519b6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/10 15:53 upstream 4a7bbe7519b6 77b23aa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in do_fcntl / do_fcntl
2024/02/06 14:29 upstream 99bd3cb0d12e 6404acf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in do_fcntl / do_fcntl
2024/02/02 08:26 upstream 5c24e4e9e708 d61103fc .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.