syzbot


KCSAN: data-race in bprm_execve / copy_fs (2)

Status: moderation: reported on 2024/04/16 23:09
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+8aa70b98cc46b42f3b46@syzkaller.appspotmail.com
First crash: 34d, last: 34d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in bprm_execve / copy_fs fs mm 3 552d 613d 0/26 auto-obsoleted due to no activity on 2023/01/03 10:25

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

write to 0xffff8881040db0d0 of 4 bytes by task 17380 on cpu 0:
 bprm_execve+0x971/0xc60 fs/exec.c:1897
 do_execveat_common+0x768/0x7d0 fs/exec.c:1979
 do_execveat fs/exec.c:2064 [inline]
 __do_sys_execveat fs/exec.c:2138 [inline]
 __se_sys_execveat fs/exec.c:2132 [inline]
 __x64_sys_execveat+0x75/0x90 fs/exec.c:2132
 x64_sys_call+0x2b9f/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:323
 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+0x77/0x7f

read to 0xffff8881040db0d0 of 4 bytes by task 17375 on cpu 1:
 copy_fs+0x95/0xf0 kernel/fork.c:1754
 copy_process+0xe6c/0x1f80 kernel/fork.c:2380
 create_io_thread+0x9e/0xd0 kernel/fork.c:2744
 create_worker_cont+0x5b/0x350 io_uring/io-wq.c:774
 task_work_run+0x13a/0x1a0 kernel/task_work.c:180
 get_signal+0xeee/0x1080 kernel/signal.c:2683
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17375 Comm: syz-executor.4 Tainted: G        W          6.9.0-rc4-syzkaller-00031-g96fca68c4fbf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/16 23:08 upstream 96fca68c4fbf 18f6e127 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bprm_execve / copy_fs
* Struck through repros no longer work on HEAD.