syzbot


KCSAN: data-race in bcm_connect / bcm_sendmsg (4)

Status: auto-closed as invalid on 2022/03/19 14:46
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 287d, last: 287d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in bcm_connect / bcm_sendmsg (3) 1 717d 717d 0/24 auto-closed as invalid on 2021/01/13 02:26
upstream KCSAN: data-race in bcm_connect / bcm_sendmsg 1 1113d 1113d 0/24 closed as invalid on 2019/11/19 14:44
upstream KCSAN: data-race in bcm_connect / bcm_sendmsg (2) 1 921d 921d 0/24 closed as invalid on 2020/06/18 14:13

Sample crash report:
==================================================================
BUG: KCSAN: data-race in bcm_connect / bcm_sendmsg

write to 0xffff8881370e5f08 of 4 bytes by task 28645 on cpu 0:
 bcm_connect+0x1f4/0x290 net/can/bcm.c:1621
 __sys_connect_file net/socket.c:1900 [inline]
 __sys_connect+0x197/0x1b0 net/socket.c:1917
 __do_sys_connect net/socket.c:1927 [inline]
 __se_sys_connect net/socket.c:1924 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1924
 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 0xffff8881370e5f08 of 4 bytes by task 28647 on cpu 1:
 bcm_sendmsg+0x6d/0x2e10 net/can/bcm.c:1283
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmsg+0x195/0x230 net/socket.c:2496
 __do_sys_sendmsg net/socket.c:2505 [inline]
 __se_sys_sendmsg net/socket.c:2503 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
 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: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 28647 Comm: syz-executor.5 Not tainted 5.17.0-rc3-syzkaller-00247-g83e396641110-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 2022/02/12 14:41 upstream 83e396641110 8b9ca619 .config log report info KCSAN: data-race in bcm_connect / bcm_sendmsg
* Struck through repros no longer work on HEAD.