syzbot


KCSAN: data-race in do_recvmmsg / unix_dgram_poll

Status: auto-closed as invalid on 2022/06/02 19:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 273d, last: 218d

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

write to 0xffff8881291bd828 of 4 bytes by task 3747 on cpu 1:
 do_recvmmsg+0x967/0xa20 net/socket.c:2824
 __sys_recvmmsg net/socket.c:2847 [inline]
 __do_sys_recvmmsg net/socket.c:2870 [inline]
 __se_sys_recvmmsg net/socket.c:2863 [inline]
 __x64_sys_recvmmsg+0xde/0x160 net/socket.c:2863
 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 0xffff8881291bd828 of 4 bytes by task 3754 on cpu 0:
 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]
 do_pollfd fs/select.c:873 [inline]
 do_poll fs/select.c:921 [inline]
 do_sys_poll+0x6d5/0xca0 fs/select.c:1015
 __do_sys_ppoll fs/select.c:1121 [inline]
 __se_sys_ppoll+0x195/0x1d0 fs/select.c:1101
 __x64_sys_ppoll+0x63/0x70 fs/select.c:1101
 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: 0x00000000 -> 0x0000000e

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3754 Comm: syz-executor.2 Not tainted 5.18.0-rc4-syzkaller-00083-g259b897e5a79-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/04/28 19:32 upstream 259b897e5a79 e9076525 .config log report info KCSAN: data-race in do_recvmmsg / unix_dgram_poll
ci2-upstream-kcsan-gce 2022/03/27 18:20 upstream f022814633e1 89bc8608 .config log report info KCSAN: data-race in do_recvmmsg / unix_dgram_poll
ci2-upstream-kcsan-gce 2022/03/09 20:24 upstream 330f4c53d3c2 9e8eaa75 .config log report info KCSAN: data-race in do_recvmmsg / unix_dgram_poll
ci2-upstream-kcsan-gce 2022/03/06 02:56 upstream 0014404f9c18 7bdd8b2c .config log report info KCSAN: data-race in do_recvmmsg / unix_dgram_poll
ci2-upstream-kcsan-gce 2022/03/05 11:13 upstream ac84e82f78cb 45a13a73 .config log report info KCSAN: data-race in do_recvmmsg / unix_dgram_poll
* Struck through repros no longer work on HEAD.