syzbot


KCSAN: data-race in do_epoll_wait / ep_poll_callback (8)

Status: auto-closed as invalid on 2022/05/01 05:30
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 251d, last: 251d
similar bugs (7):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_epoll_wait / ep_poll_callback (7) 1 300d 300d 0/24 auto-closed as invalid on 2022/03/12 11:24
upstream KCSAN: data-race in do_epoll_wait / ep_poll_callback (6) 1 342d 342d 0/24 auto-closed as invalid on 2022/01/29 14:05
upstream KCSAN: data-race in do_epoll_wait / ep_poll_callback (2) 2 664d 666d 0/24 auto-closed as invalid on 2021/03/14 02:07
upstream KCSAN: data-race in do_epoll_wait / ep_poll_callback (5) 2 448d 459d 0/24 auto-closed as invalid on 2021/10/15 22:14
upstream KCSAN: data-race in do_epoll_wait / ep_poll_callback (4) 1 541d 541d 0/24 auto-closed as invalid on 2021/07/14 13:56
upstream KCSAN: data-race in do_epoll_wait / ep_poll_callback (3) 1 611d 611d 0/24 auto-closed as invalid on 2021/05/17 11:16
upstream KCSAN: data-race in do_epoll_wait / ep_poll_callback 221 851d 888d 0/24 auto-closed as invalid on 2020/08/31 10:40

Sample crash report:
==================================================================
BUG: KCSAN: data-race in do_epoll_wait / ep_poll_callback

write to 0xffff8881368aab68 of 4 bytes by task 31611 on cpu 0:
 ep_send_events fs/eventpoll.c:1706 [inline]
 ep_poll fs/eventpoll.c:1806 [inline]
 do_epoll_wait+0x8a3/0xf50 fs/eventpoll.c:2234
 do_epoll_pwait fs/eventpoll.c:2268 [inline]
 __do_sys_epoll_pwait fs/eventpoll.c:2281 [inline]
 __se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275
 __x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881368aab68 of 4 bytes by task 31616 on cpu 1:
 ep_poll_callback+0x415/0x4e0 fs/eventpoll.c:1213
 __wake_up_common+0xbc/0x130 kernel/sched/wait.c:107
 __wake_up_common_lock kernel/sched/wait.c:137 [inline]
 __wake_up+0x80/0xc0 kernel/sched/wait.c:156
 sock_def_wakeup+0x59/0x70 net/core/sock.c:3139
 inet_shutdown+0x1e4/0x200 net/ipv4/af_inet.c:909
 __sys_shutdown_sock net/socket.c:2252 [inline]
 __sys_shutdown net/socket.c:2264 [inline]
 __do_sys_shutdown net/socket.c:2272 [inline]
 __se_sys_shutdown+0xf6/0x140 net/socket.c:2270
 __x64_sys_shutdown+0x2d/0x40 net/socket.c:2270
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x60000019 -> 0x60000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 31616 Comm: syz-executor.4 Not tainted 5.17.0-syzkaller-10753-gbddac7c1e02b-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 2022/03/27 05:28 upstream bddac7c1e02b 89bc8608 .config log report info KCSAN: data-race in do_epoll_wait / ep_poll_callback
* Struck through repros no longer work on HEAD.