syzbot


KCSAN: data-race in unix_poll / unix_release_sock (3)

Status: auto-closed as invalid on 2022/08/12 09:16
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 152d, last: 152d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in unix_poll / unix_release_sock (5) 1 68d 68d 0/24 auto-obsoleted due to no activity on 2022/11/04 19:08
upstream KCSAN: data-race in unix_poll / unix_release_sock 1 600d 600d 0/24 auto-closed as invalid on 2021/05/21 02:26
upstream KCSAN: data-race in unix_poll / unix_release_sock (4) 1 105d 105d 0/24 auto-closed as invalid on 2022/09/28 03:19
upstream KCSAN: data-race in unix_poll / unix_release_sock (2) 1 560d 560d 0/24 auto-closed as invalid on 2021/06/30 15:16

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

write to 0xffff88812e0c0260 of 4 bytes by task 4642 on cpu 0:
 unix_release_sock+0x30e/0x6a0 net/unix/af_unix.c:609
 unix_release+0x4e/0x70 net/unix/af_unix.c:990
 __sock_release net/socket.c:650 [inline]
 sock_close+0x6c/0x150 net/socket.c:1365
 __fput+0x292/0x510 fs/file_table.c:317
 ____fput+0x11/0x20 fs/file_table.c:350
 task_work_run+0x8e/0x110 kernel/task_work.c:177
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x124/0x130 kernel/entry/common.c:169
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff88812e0c0260 of 4 bytes by task 4643 on cpu 1:
 unix_poll+0x6d/0x250 net/unix/af_unix.c:3125
 sock_poll+0x23e/0x260 net/socket.c:1353
 vfs_poll include/linux/poll.h:88 [inline]
 io_poll_check_events+0x1ee/0x4f0 fs/io_uring.c:6870
 io_apoll_task_func+0x36/0x2f0 fs/io_uring.c:6943
 handle_tw_list fs/io_uring.c:2930 [inline]
 tctx_task_work+0x8d0/0xc10 fs/io_uring.c:2959
 task_work_run+0x8e/0x110 kernel/task_work.c:177
 get_signal+0xeca/0x1020 kernel/signal.c:2634
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:166
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x00000000 -> 0x00000068

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4643 Comm: syz-executor.4 Not tainted 5.19.0-rc5-syzkaller-00187-ge8a4e1c1bb69-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/07/08 09:15 upstream e8a4e1c1bb69 8442e655 .config log report info KCSAN: data-race in unix_poll / unix_release_sock
* Struck through repros no longer work on HEAD.