syzbot


KCSAN: data-race in packet_setsockopt / packet_setsockopt

Status: internal: reported on 2022/01/25 17:51
Reported-by: syzbot+@syzkaller.appspotmail.com
Fix commit: e42e70ad6ae2 af_packet: fix data-race in packet_setsockopt / packet_setsockopt
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: 166d, last: 166d

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

write to 0xffff88813ae8e300 of 8 bytes by task 14653 on cpu 0:
 fanout_add net/packet/af_packet.c:1791 [inline]
 packet_setsockopt+0x22fe/0x24a0 net/packet/af_packet.c:3931
 __sys_setsockopt+0x209/0x2a0 net/socket.c:2180
 __do_sys_setsockopt net/socket.c:2191 [inline]
 __se_sys_setsockopt net/socket.c:2188 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2188
 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 0xffff88813ae8e300 of 8 bytes by task 14654 on cpu 1:
 packet_setsockopt+0x691/0x24a0 net/packet/af_packet.c:3935
 __sys_setsockopt+0x209/0x2a0 net/socket.c:2180
 __do_sys_setsockopt net/socket.c:2191 [inline]
 __se_sys_setsockopt net/socket.c:2188 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2188
 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: 0x0000000000000000 -> 0xffff888106f8c000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14654 Comm: syz-executor.3 Not tainted 5.16.0-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 2022/01/13 06:37 upstream f079ab01b560 44d1319a .config log report info KCSAN: data-race in packet_setsockopt / packet_setsockopt