syzbot


KCSAN: data-race in macvlan_broadcast / macvlan_dev_get_stats64

Status: auto-closed as invalid on 2022/06/03 01:27
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 211d, last: 211d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in macvlan_broadcast / macvlan_dev_get_stats64

read-write to 0xffffe8fffee19430 of 8 bytes by task 34 on cpu 0:
 macvlan_count_rx include/linux/if_macvlan.h:50 [inline]
 macvlan_broadcast+0x2f5/0x400 drivers/net/macvlan.c:289
 macvlan_process_broadcast+0x2a7/0x330 drivers/net/macvlan.c:314
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffffe8fffee19430 of 8 bytes by task 1478 on cpu 1:
 macvlan_dev_get_stats64+0x147/0x2c0 drivers/net/macvlan.c:954
 dev_get_stats+0x69/0x240 net/core/dev.c:10344
 rtnl_fill_stats+0x45/0x320 net/core/rtnetlink.c:1203
 rtnl_fill_ifinfo+0xc19/0x1050 net/core/rtnetlink.c:1778
 rtnl_dump_ifinfo+0x87c/0xcb0 net/core/rtnetlink.c:2143
 netlink_dump+0x38c/0x720 net/netlink/af_netlink.c:2277
 netlink_recvmsg+0x46f/0x790 net/netlink/af_netlink.c:2004
 ____sys_recvmsg+0x162/0x2f0
 ___sys_recvmsg net/socket.c:2674 [inline]
 __sys_recvmsg+0x209/0x3f0 net/socket.c:2704
 __do_sys_recvmsg net/socket.c:2714 [inline]
 __se_sys_recvmsg net/socket.c:2711 [inline]
 __x64_sys_recvmsg+0x42/0x50 net/socket.c:2711
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000000003c92f -> 0x000000000003c95d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1478 Comm: dhcpcd Not tainted 5.18.0-rc4-syzkaller-00083-g259b897e5a79-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 2022/04/29 01:21 upstream 259b897e5a79 e9076525 .config log report info KCSAN: data-race in macvlan_broadcast / macvlan_dev_get_stats64
* Struck through repros no longer work on HEAD.