syzbot


KCSAN: data-race in tcp_connect / tcp_poll

Status: auto-closed as invalid on 2022/02/22 00:27
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 339d, last: 319d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in tcp_connect / tcp_poll

write to 0xffff888135f1e328 of 4 bytes by task 1536 on cpu 1:
 tcp_connect_init net/ipv4/tcp_output.c:3678 [inline]
 tcp_connect+0xa62/0x1d90 net/ipv4/tcp_output.c:3818
 tcp_v4_connect+0xadf/0xbb0 net/ipv4/tcp_ipv4.c:312
 __inet_stream_connect+0x156/0x6e0 net/ipv4/af_inet.c:660
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1162 [inline]
 tcp_sendmsg_locked+0x2464/0x25a0 net/ipv4/tcp.c:1204
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1440
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 __sys_sendto+0x21e/0x2c0 net/socket.c:2040
 __do_sys_sendto net/socket.c:2052 [inline]
 __se_sys_sendto net/socket.c:2048 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2048
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888135f1e328 of 4 bytes by task 1537 on cpu 0:
 tcp_poll+0x4a6/0x580 net/ipv4/tcp.c:588
 sock_poll+0x23e/0x260 net/socket.c:1306
 vfs_poll include/linux/poll.h:90 [inline]
 do_select+0x7a5/0xeb0 fs/select.c:538
 core_sys_select+0x440/0x6d0 fs/select.c:681
 kern_select fs/select.c:722 [inline]
 __do_sys_select fs/select.c:729 [inline]
 __se_sys_select+0x1a7/0x1e0 fs/select.c:726
 __x64_sys_select+0x63/0x70 fs/select.c:726
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000006f -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1537 Comm: syz-executor.5 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/01/18 00:21 upstream 0c947b893d69 731a2d23 .config log report info KCSAN: data-race in tcp_connect / tcp_poll
ci2-upstream-kcsan-gce 2021/12/29 01:12 upstream ecf71de775a0 76c8cf06 .config log report info KCSAN: data-race in tcp_connect / tcp_poll
* Struck through repros no longer work on HEAD.