syzbot


KCSAN: data-race in l2cap_chan_connect / l2cap_sock_bind

Status: moderation: reported on 2024/06/05 01:51
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+a6d6de7973ae8920f5ce@syzkaller.appspotmail.com
First crash: 10d, last: 10d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in l2cap_chan_connect / l2cap_sock_bind

write to 0xffff88811c45f41e of 1 bytes by task 17884 on cpu 1:
 l2cap_sock_bind+0x30e/0x520 net/bluetooth/l2cap_sock.c:133
 __sys_bind+0x15b/0x1d0 net/socket.c:1847
 __do_sys_bind net/socket.c:1858 [inline]
 __se_sys_bind net/socket.c:1856 [inline]
 __x64_sys_bind+0x41/0x50 net/socket.c:1856
 x64_sys_call+0x25b5/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:50
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811c45f41e of 1 bytes by task 17885 on cpu 0:
 l2cap_chan_connect+0x4c/0x980 net/bluetooth/l2cap_core.c:6960
 l2cap_sock_connect+0x3c4/0x450 net/bluetooth/l2cap_sock.c:256
 __sys_connect_file net/socket.c:2049 [inline]
 __sys_connect+0x1a9/0x1c0 net/socket.c:2066
 __do_sys_connect net/socket.c:2076 [inline]
 __se_sys_connect net/socket.c:2073 [inline]
 __x64_sys_connect+0x41/0x50 net/socket.c:2073
 x64_sys_call+0x2961/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:43
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17885 Comm: syz-executor.1 Not tainted 6.10.0-rc2-syzkaller-00022-g32f88d65f01b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/05 01:50 upstream 32f88d65f01b e1e2c66e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in l2cap_chan_connect / l2cap_sock_bind
* Struck through repros no longer work on HEAD.