syzbot


KCSAN: data-race in inet_send_prepare / udp_lib_get_port (3)
Status: fixed on 2021/11/10 00:50
Reported-by: syzbot+@syzkaller.appspotmail.com
Fix commit: dcd01eeac144 inet: annotate data race in inet_send_prepare() and inet_dgram_connect()
First crash: 348d, last: 345d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in inet_send_prepare / udp_lib_get_port (2) 1 399d 399d 0/22 auto-closed as invalid on 2021/05/21 15:38
upstream KCSAN: data-race in inet_send_prepare / udp_lib_get_port 1 924d 924d 0/22 closed as invalid on 2019/11/19 14:44

Sample crash report:
==================================================================
BUG: KCSAN: data-race in inet_send_prepare / udp_lib_get_port

write to 0xffff88812e04a00e of 2 bytes by task 16676 on cpu 1:
 udp_lib_get_port+0x4b2/0xe20 net/ipv4/udp.c:308
 udp_v6_get_port+0x5e/0x70 net/ipv6/udp.c:89
 inet_autobind net/ipv4/af_inet.c:183 [inline]
 inet_dgram_connect+0x12a/0x180 net/ipv4/af_inet.c:578
 __sys_connect_file net/socket.c:1837 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1854
 __do_sys_connect net/socket.c:1864 [inline]
 __se_sys_connect net/socket.c:1861 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1861
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812e04a00e of 2 bytes by task 16693 on cpu 0:
 inet_send_prepare+0x21/0x210 net/ipv4/af_inet.c:806
 inet6_sendmsg+0x29/0x80 net/ipv6/af_inet6.c:639
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0xb52b

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16693 Comm: syz-executor.3 Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/06/10 11:44 upstream cd1245d75ce9 1ba81399 .config log report info KCSAN: data-race in inet_send_prepare / udp_lib_get_port
ci2-upstream-kcsan-gce 2021/06/08 22:07 upstream 4c8684fe555e 5c2fe346 .config log report info KCSAN: data-race in inet_send_prepare / udp_lib_get_port
ci2-upstream-kcsan-gce 2021/06/08 00:19 upstream 614124bea77e b718257f .config log report info KCSAN: data-race in inet_send_prepare / udp_lib_get_port
ci2-upstream-kcsan-gce 2021/06/06 22:32 upstream decad3e1d1ed 500c2339 .config log report info KCSAN: data-race in inet_send_prepare / udp_lib_get_port