syzbot


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

Status: auto-closed as invalid on 2021/12/20 20:13
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 432d, last: 375d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in unix_dgram_poll / unix_release_sock (5) 1 203d 203d 0/24 auto-closed as invalid on 2022/06/11 02:26
upstream KCSAN: data-race in unix_dgram_poll / unix_release_sock (2) 14 471d 510d 0/24 auto-closed as invalid on 2021/09/16 16:01
upstream KCSAN: data-race in unix_dgram_poll / unix_release_sock (4) 1 248d 248d 0/24 auto-closed as invalid on 2022/04/27 04:20
upstream KCSAN: data-race in unix_dgram_poll / unix_release_sock 6 555d 578d 0/24 auto-closed as invalid on 2021/06/23 23:39

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

write to 0xffff8881031eefb0 of 4 bytes by task 20248 on cpu 0:
 unix_release_sock+0x2e9/0x680 net/unix/af_unix.c:567
 unix_release+0x4e/0x70 net/unix/af_unix.c:949
 __sock_release net/socket.c:649 [inline]
 sock_close+0x6c/0x150 net/socket.c:1314
 __fput+0x295/0x520 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [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 0xffff8881031eefb0 of 4 bytes by task 20257 on cpu 1:
 unix_dgram_poll+0x6e/0x3e0 net/unix/af_unix.c:3084
 sock_poll+0x23e/0x260 net/socket.c:1302
 vfs_poll include/linux/poll.h:90 [inline]
 io_poll_rewait fs/io_uring.c:5298 [inline]
 io_async_task_func+0x182/0x713 fs/io_uring.c:5521
 tctx_task_work+0x25a/0x410 fs/io_uring.c:2206
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:214 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x102/0x190 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: 0x00000000 -> 0x00000068

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20257 Comm: syz-executor.5 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (6):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/11/15 20:06 upstream 8ab774587903 75b04091 .config log report info KCSAN: data-race in unix_dgram_poll / unix_release_sock
ci2-upstream-kcsan-gce 2021/10/14 19:38 upstream 26d657410983 7aa5fe41 .config log report info KCSAN: data-race in unix_dgram_poll / unix_release_sock
ci2-upstream-kcsan-gce 2021/09/26 18:34 upstream a3b397b4fffb 8cac236e .config log report info KCSAN: data-race in unix_dgram_poll / unix_release_sock
ci2-upstream-kcsan-gce 2021/09/25 06:26 upstream 7d42e9818258 8cac236e .config log report info KCSAN: data-race in unix_dgram_poll / unix_release_sock
ci2-upstream-kcsan-gce 2021/09/22 11:42 upstream 92477dd1faa6 169724fe .config log report info KCSAN: data-race in unix_dgram_poll / unix_release_sock
ci2-upstream-kcsan-gce 2021/09/20 06:43 upstream 20621d2f27a0 70b76c1d .config log report info KCSAN: data-race in unix_dgram_poll / unix_release_sock
* Struck through repros no longer work on HEAD.