syzbot


KCSAN: data-race in fasync_remove_entry / sock_wake_async (8)

Status: auto-closed as invalid on 2022/04/26 03:12
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 260d, last: 260d
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 837d 837d 0/24 auto-closed as invalid on 2020/09/26 10:37
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async 1 995d 995d 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 564d 601d 0/24 auto-closed as invalid on 2021/06/26 18:07
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (6) 2 360d 388d 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 921d 921d 0/24 closed as invalid on 2020/06/18 14:13
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (9) 2 44d 50d 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 889d 889d 0/24 auto-closed as invalid on 2020/08/05 10:16
upstream KCSAN: data-race in fasync_remove_entry / sock_wake_async (7) 1 306d 306d 0/24 auto-closed as invalid on 2022/03/11 19:41

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

write to 0xffff88813a0cd058 of 8 bytes by task 13171 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:314
 ____fput+0x11/0x20 fs/file_table.c:350
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 get_signal+0x1570/0x15b0 kernel/signal.c:2631
 arch_do_signal_or_restart+0x8c/0x2e0 arch/x86/kernel/signal.c:868
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x113/0x190 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 0xffff88813a0cd058 of 8 bytes by task 13173 on cpu 1:
 sock_wake_async+0x26/0x100 net/socket.c:1358
 sk_wake_async include/net/sock.h:2444 [inline]
 unix_write_space+0x128/0x140 net/unix/af_unix.c:518
 sock_wfree+0xaf/0x150 net/core/sock.c:2296
 unix_destruct_scm+0x164/0x190 net/unix/scm.c:152
 skb_release_head_state+0xb3/0x1a0 net/core/skbuff.c:729
 skb_release_all net/core/skbuff.c:740 [inline]
 __kfree_skb+0x14/0x150 net/core/skbuff.c:756
 kfree_skb_reason+0x52/0x170 net/core/skbuff.c:776
 kfree_skb include/linux/skbuff.h:1114 [inline]
 unix_release_sock+0x557/0x6a0 net/unix/af_unix.c:626
 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:317
 ____fput+0x11/0x20 fs/file_table.c:350
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 get_signal+0x1570/0x15b0 kernel/signal.c:2631
 arch_do_signal_or_restart+0x8c/0x2e0 arch/x86/kernel/signal.c:868
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x113/0x190 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: 0xffff88813e699060 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13173 Comm: syz-executor.3 Not tainted 5.17.0-syzkaller-00192-geaa54b1458ca-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 2022/03/22 02:51 upstream eaa54b1458ca e2d91b1d .config log report info KCSAN: data-race in fasync_remove_entry / sock_wake_async
* Struck through repros no longer work on HEAD.