syzbot


KCSAN: data-race in __ip4_datagram_connect / raw_bind (2)
Status: internal: reported on 2022/01/25 17:51
Reported-by: syzbot+@syzkaller.appspotmail.com
Fix commit: 153a0d187e76 ipv4: raw: lock the socket in raw_bind()
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce ci-upstream-kmsan-gce-386 ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-riscv64]
First crash: 120d, last: 120d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __ip4_datagram_connect / raw_bind 1 942d 942d 16/22 fixed on 2019/12/13 00:31

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __ip4_datagram_connect / raw_bind

write to 0xffff8881170d4308 of 4 bytes by task 5466 on cpu 0:
 raw_bind+0x1b0/0x250 net/ipv4/raw.c:739
 inet_bind+0x56/0xa0 net/ipv4/af_inet.c:443
 __sys_bind+0x14b/0x1b0 net/socket.c:1697
 __do_sys_bind net/socket.c:1708 [inline]
 __se_sys_bind net/socket.c:1706 [inline]
 __x64_sys_bind+0x3d/0x50 net/socket.c:1706
 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 0xffff8881170d4308 of 4 bytes by task 5468 on cpu 1:
 __ip4_datagram_connect+0xb7/0x7b0 net/ipv4/datagram.c:39
 ip4_datagram_connect+0x2a/0x40 net/ipv4/datagram.c:89
 inet_dgram_connect+0x107/0x190 net/ipv4/af_inet.c:576
 __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

value changed: 0x00000000 -> 0x0003007f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5468 Comm: syz-executor.5 Not tainted 5.17.0-rc1-syzkaller #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 2022/01/25 05:47 upstream dd81e1c7d5fb 2cbffd88 .config log report info KCSAN: data-race in __ip4_datagram_connect / raw_bind