syzbot


KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (2)

Status: auto-closed as invalid on 2020/12/25 10:44
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+a27265bf496b8672a66a@syzkaller.appspotmail.com
First crash: 1247d, last: 1226d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll net 5 1344d 1374d 0/26 auto-closed as invalid on 2020/08/27 17:47
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (3) net 4 1121d 1164d 0/26 auto-closed as invalid on 2021/04/07 19:26
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (6) net 1 881d 881d 0/26 auto-closed as invalid on 2021/12/03 15:30
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (5) net 1 958d 958d 0/26 auto-closed as invalid on 2021/09/17 19:26
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (4) net 2 1040d 1056d 0/26 auto-closed as invalid on 2021/06/27 09:27

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

write to 0xffff8881066cde30 of 4 bytes by task 10041 on cpu 1:
 unix_dgram_disconnected net/unix/af_unix.c:486 [inline]
 unix_dgram_connect+0x792/0x860 net/unix/af_unix.c:1190
 __sys_connect_file net/socket.c:1852 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1869
 __do_sys_connect net/socket.c:1879 [inline]
 __se_sys_connect net/socket.c:1876 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1876
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881066cde30 of 4 bytes by task 10031 on cpu 0:
 unix_dgram_poll+0x6e/0x3b0 net/unix/af_unix.c:2692
 sock_poll+0x188/0x1a0 net/socket.c:1265
 vfs_poll include/linux/poll.h:90 [inline]
 ep_item_poll fs/eventpoll.c:885 [inline]
 ep_send_events_proc+0x227/0x5f0 fs/eventpoll.c:1742
 ep_scan_ready_list+0x13e/0x330 fs/eventpoll.c:712
 ep_send_events fs/eventpoll.c:1786 [inline]
 ep_poll fs/eventpoll.c:1942 [inline]
 do_epoll_wait+0x4b2/0x810 fs/eventpoll.c:2323
 __do_sys_epoll_wait fs/eventpoll.c:2333 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2330 [inline]
 __x64_sys_epoll_wait+0x4d/0x60 fs/eventpoll.c:2330
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10031 Comm: syz-executor.3 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/18 23:48 upstream c2e7554e1b85 0767f13f .config console log report info ci2-upstream-kcsan-gce
2020/11/06 01:34 upstream 521b619acdc8 cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/10/28 17:39 upstream ed8780e3f2ec f24824d3 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.