syzbot


KCSAN: data-race in dccp_connect / dccp_poll

Status: auto-closed as invalid on 2022/03/23 08:39
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 300d, last: 290d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in dccp_connect / dccp_poll

write to 0xffff8881020904a8 of 4 bytes by task 10152 on cpu 0:
 dccp_connect+0x31/0x400 net/dccp/output.c:548
 dccp_v4_connect+0x825/0x8a0 net/dccp/ipv4.c:129
 __inet_stream_connect+0x156/0x6e0 net/ipv4/af_inet.c:660
 inet_stream_connect+0x44/0x70 net/ipv4/af_inet.c:724
 __sys_connect_file+0xd3/0xe0 net/socket.c:1900
 io_connect fs/io_uring.c:5352 [inline]
 io_issue_sqe+0x41a4/0x9610 fs/io_uring.c:6791
 __io_queue_sqe+0x20/0x6a0 fs/io_uring.c:7097
 io_req_task_submit+0x8b/0xf0 fs/io_uring.c:2441
 handle_tw_list fs/io_uring.c:2328 [inline]
 tctx_task_work+0x8b2/0xc90 fs/io_uring.c:2362
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:213 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x102/0x190 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300
 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881020904a8 of 4 bytes by task 10163 on cpu 1:
 dccp_poll+0xbb/0x3c0 net/dccp/proto.c:323
 sock_poll+0x23e/0x260 net/socket.c:1306
 vfs_poll include/linux/poll.h:88 [inline]
 do_select+0x7a5/0xeb0 fs/select.c:538
 core_sys_select+0x440/0x6d0 fs/select.c:681
 do_pselect fs/select.c:763 [inline]
 __do_sys_pselect6+0x1ea/0x250 fs/select.c:804
 __se_sys_pselect6 fs/select.c:795 [inline]
 __x64_sys_pselect6+0x74/0x80 fs/select.c:795
 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: 1 PID: 10163 Comm: syz-executor.0 Not tainted 5.17.0-rc4-syzkaller-00051-gc5d9ae265b10-dirty #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 2022/02/16 08:33 upstream c5d9ae265b10 8b9ca619 .config log report info KCSAN: data-race in dccp_connect / dccp_poll
ci2-upstream-kcsan-gce 2022/02/05 23:14 upstream 0457e5153e0e a7dab638 .config log report info KCSAN: data-race in dccp_connect / dccp_poll
* Struck through repros no longer work on HEAD.