syzbot


KCSAN: data-race in fasync_remove_entry / sock_wake_async (7)

Status: auto-closed as invalid on 2022/03/11 19:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 303d, last: 303d
similar bugs (8):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (4) 1 835d 835d 0/24 auto-closed as invalid on 2020/09/26 10:37
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async 1 992d 992d 0/24 auto-closed as invalid on 2020/05/26 22:23
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (5) 3 562d 598d 0/24 auto-closed as invalid on 2021/06/26 18:07
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (8) 1 258d 258d 0/24 auto-closed as invalid on 2022/04/26 03:12
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (6) 2 358d 385d 0/24 auto-closed as invalid on 2022/01/16 09:31
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (2) 1 919d 919d 0/24 closed as invalid on 2020/06/18 14:13
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (9) 2 42d 48d 0/24 auto-obsoleted due to no activity on 2022/11/28 02:38
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (3) 1 887d 887d 0/24 auto-closed as invalid on 2020/08/05 10:16

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

write to 0xffff88813f820cd8 of 8 bytes by task 20076 on cpu 0:
 fasync_remove_entry+0xd5/0x140 fs/fcntl.c:895
 fasync_helper+0x92/0xc0 fs/fcntl.c:994
 sock_fasync+0x5c/0xc0 net/socket.c:1343
 __fput+0x4dd/0x520 fs/file_table.c:308
 ____fput+0x11/0x20 fs/file_table.c:344
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x160/0x190 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300
 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813f820cd8 of 8 bytes by task 20058 on cpu 1:
 sock_wake_async+0x26/0x100 net/socket.c:1358
 sk_wake_async include/net/sock.h:2444 [inline]
 unix_release_sock+0x38d/0x6a0 net/unix/af_unix.c:612
 unix_release+0x4e/0x70 net/unix/af_unix.c:990
 __sock_release net/socket.c:650 [inline]
 sock_close+0x6c/0x150 net/socket.c:1318
 __fput+0x295/0x520 fs/file_table.c:311
 ____fput+0x11/0x20 fs/file_table.c:344
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x160/0x190 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300
 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff8881369b7f30 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20058 Comm: syz-executor.1 Not tainted 5.17.0-rc2-syzkaller-00167-gdcb85f85fa6f-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/04 19:40 upstream dcb85f85fa6f a3e470b2 .config log report info KCSAN: data-race in fasync_remove_entry / sock_wake_async
* Struck through repros no longer work on HEAD.