syzbot


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

Status: auto-closed as invalid on 2021/09/17 19:26
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 474d, last: 474d
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 5 860d 890d 0/24 auto-closed as invalid on 2020/08/27 17:47
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (3) 4 637d 680d 0/24 auto-closed as invalid on 2021/04/07 19:26
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (6) 1 397d 397d 0/24 auto-closed as invalid on 2021/12/03 15:30
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (2) 3 742d 719d 0/24 auto-closed as invalid on 2020/12/25 10:44
upstream KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (4) 2 556d 572d 0/24 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 0xffff8881040cce30 of 4 bytes by task 32666 on cpu 1:
 unix_dgram_disconnected net/unix/af_unix.c:493 [inline]
 unix_dgram_connect+0x73d/0x840 net/unix/af_unix.c:1196
 __sys_connect_file net/socket.c:1879 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1896
 __do_sys_connect net/socket.c:1906 [inline]
 __se_sys_connect net/socket.c:1903 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1903
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881040cce30 of 4 bytes by task 32661 on cpu 0:
 unix_dgram_poll+0x6e/0x3e0 net/unix/af_unix.c:2745
 sock_poll+0x23e/0x260 net/socket.c:1288
 vfs_poll include/linux/poll.h:90 [inline]
 ep_item_poll fs/eventpoll.c:846 [inline]
 ep_send_events fs/eventpoll.c:1683 [inline]
 ep_poll fs/eventpoll.c:1798 [inline]
 do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2226
 __do_sys_epoll_wait fs/eventpoll.c:2238 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2233 [inline]
 __x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2233
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00000068

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 32661 Comm: syz-executor.2 Tainted: G        W         5.14.0-rc5-syzkaller #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 2021/08/13 19:17 upstream f8e6dfc64f61 2489ab88 .config log report info KCSAN: data-race in unix_dgram_connect / unix_dgram_poll
* Struck through repros no longer work on HEAD.