syzbot


KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (10)

Status: moderation: reported on 2026/03/24 09:15
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+570a19301854446f586f@syzkaller.appspotmail.com
First crash: 8d00h, last: 8d00h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
fcf2b9a4-3ec4-42a4-879b-a9bb357b401a assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (10) 2026/03/20 09:04 2026/03/20 09:04 2026/03/20 09:06 f84caa2f84dea47b51a188e8d6267f295e89bbcb
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (4) net 6 1 1118d 1118d 0/29 auto-obsoleted due to no activity on 2023/04/16 13:59
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (8) net 6 1 371d 371d 0/29 auto-obsoleted due to no activity on 2025/05/17 04:52
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (3) net 6 4 1292d 1350d 0/29 auto-obsoleted due to no activity on 2022/10/17 15:43
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (5) net 6 1 1013d 1013d 0/29 closed as invalid on 2023/06/28 10:35
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (7) net 6 2 431d 437d 0/29 auto-obsoleted due to no activity on 2025/03/18 04:41
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (6) net 6 1 917d 917d 0/29 auto-obsoleted due to no activity on 2023/10/27 23:12
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (9) net 6 10 85d 88d 0/29 auto-obsoleted due to no activity on 2026/03/09 14:50
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter (2) net 6 2 1488d 1502d 0/29 auto-closed as invalid on 2022/04/04 18:44
upstream KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter net 6 1 1524d 1524d 0/29 closed as invalid on 2022/01/25 17:50

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

read-write to 0xffff88811be7b0b0 of 4 bytes by task 13371 on cpu 1:
 ipvlan_open+0x74/0x100 drivers/net/ipvlan/ipvlan_main.c:-1
 __dev_open+0x321/0x560 net/core/dev.c:1702
 __dev_change_flags+0x13e/0x400 net/core/dev.c:9764
 rtnl_configure_link net/core/rtnetlink.c:3594 [inline]
 rtnl_newlink_create+0x392/0x650 net/core/rtnetlink.c:3850
 __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
 rtnl_newlink+0x10a0/0x1330 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6985
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5c0/0x690 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0x563/0x5b0 net/socket.c:2592
 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2681
 x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811be7b0b0 of 4 bytes by task 6907 on cpu 0:
 netif_is_bond_master include/linux/netdevice.h:5484 [inline]
 is_upper_ndev_bond_master_filter+0x2b/0xb0 drivers/infiniband/core/roce_gid_mgmt.c:275
 ib_enum_roce_netdev+0x122/0x1d0 drivers/infiniband/core/device.c:2390
 ib_enum_all_roce_netdevs+0x89/0x100 drivers/infiniband/core/device.c:2417
 netdevice_event_work_handler+0x67/0x3d0 drivers/infiniband/core/roce_gid_mgmt.c:648
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359
 worker_thread+0x58a/0x780 kernel/workqueue.c:3440
 kthread+0x22a/0x280 kernel/kthread.c:436
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00008002 -> 0x00008083

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 6907 Comm: kworker/u8:21 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: gid-cache-wq netdevice_event_work_handler
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/20 09:04 upstream 8a30aeb0d1b4 2f245add .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ipvlan_open / is_upper_ndev_bond_master_filter
* Struck through repros no longer work on HEAD.