syzbot


KCSAN: data-race in unix_dgram_poll / unix_release_sock (5)

Status: auto-closed as invalid on 2022/06/11 02:26
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 205d, last: 205d
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 (3) 6 377d 434d 0/24 auto-closed as invalid on 2021/12/20 20:13
upstream KCSAN: data-race in unix_dgram_poll / unix_release_sock (2) 14 472d 512d 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 250d 250d 0/24 auto-closed as invalid on 2022/04/27 04:20
upstream KCSAN: data-race in unix_dgram_poll / unix_release_sock 6 557d 580d 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 0xffff888127392b68 of 4 bytes by task 26290 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:1318
 __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:164
 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+0x44/0xae

read to 0xffff888127392b68 of 4 bytes by task 26291 on cpu 1:
 unix_dgram_poll+0x6e/0x3e0 net/unix/af_unix.c:3171
 sock_poll+0x23e/0x260 net/socket.c:1306
 vfs_poll include/linux/poll.h:88 [inline]
 io_poll_check_events+0x495/0x810 fs/io_uring.c:5873
 io_apoll_task_func+0x49/0x350 fs/io_uring.c:5932
 handle_tw_list fs/io_uring.c:2463 [inline]
 tctx_task_work+0x80b/0xa30 fs/io_uring.c:2497
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 get_signal+0xeca/0x1020 kernel/signal.c:2641
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:867
 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+0x44/0xae

value changed: 0x00000000 -> 0x00000068

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26291 Comm: syz-executor.0 Not tainted 5.18.0-rc5-syzkaller-00163-g4b97bac0756a-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 2022/05/07 02:19 upstream 4b97bac0756a e60b1103 .config log report info KCSAN: data-race in unix_dgram_poll / unix_release_sock
* Struck through repros no longer work on HEAD.