* [syzbot] [bpf?] [net?] possible deadlock in xsk_diag_dump (3)
@ 2026-08-24 19:47 syzbot
0 siblings, 0 replies; only message in thread
From: syzbot @ 2026-08-24 19:47 UTC (permalink / raw)
To: andrii, ast, bpf, daniel, davem, edumazet, horms, kuba,
linux-kernel, maciej.fijalkowski, magnus.karlsson, netdev,
pabeni, sdf, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 26260251022f Merge tag 'livepatching-for-7.3' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=100d4415580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b5a17c415a27e42e
dashboard link: https://syzkaller.appspot.com/bug?extid=aa48b5fe7bfda62d1682
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/05f9f33a1f1f/disk-26260251.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/197f5b9a6961/vmlinux-26260251.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ad671f043000/bzImage-26260251.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+aa48b5fe7bfda62d1682@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.6.13158/8347 is trying to acquire lock:
ffff888063c308f0 (&xs->mutex){+.+.}-{4:4}, at: xsk_diag_fill net/xdp/xsk_diag.c:113 [inline]
ffff888063c308f0 (&xs->mutex){+.+.}-{4:4}, at: xsk_diag_dump+0x533/0x1560 net/xdp/xsk_diag.c:166
but task is already holding lock:
ffff888061732440 (&net->xdp.lock){+.+.}-{4:4}, at: xsk_diag_dump+0x184/0x1560 net/xdp/xsk_diag.c:158
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&net->xdp.lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578
xsk_notifier+0x89/0x230 net/xdp/xsk.c:2106
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
call_netdevice_notifiers net/core/dev.c:2327 [inline]
unregister_netdevice_many_notify+0x17fa/0x2130 net/core/dev.c:12518
ipvlan_device_event+0xf1f/0xfb0 drivers/net/ipvlan/ipvlan_main.c:851
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
call_netdevice_notifiers net/core/dev.c:2327 [inline]
unregister_netdevice_many_notify+0x17fa/0x2130 net/core/dev.c:12518
rtnl_delete_link net/core/rtnetlink.c:3652 [inline]
rtnl_dellink+0x5be/0x810 net/core/rtnetlink.c:3694
rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
__sock_sendmsg net/socket.c:815 [inline]
____sys_sendmsg+0x565/0x870 net/socket.c:2713
___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
__sys_sendmsg net/socket.c:2799 [inline]
__do_sys_sendmsg net/socket.c:2804 [inline]
__se_sys_sendmsg net/socket.c:2802 [inline]
__x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2802
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #2 (&port->pnodes_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578
ipvlan_device_event+0x489/0xfb0 drivers/net/ipvlan/ipvlan_main.c:810
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
call_netdevice_notifiers net/core/dev.c:2327 [inline]
netdev_features_change net/core/dev.c:1612 [inline]
netdev_change_features net/core/dev.c:11182 [inline]
netdev_compute_master_upper_features+0x944/0xb30 net/core/dev.c:13069
bond_slave_netdev_event drivers/net/bonding/bond_main.c:4045 [inline]
bond_netdev_event+0x7a3/0xf80 drivers/net/bonding/bond_main.c:4090
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
call_netdevice_notifiers net/core/dev.c:2327 [inline]
netdev_features_change net/core/dev.c:1612 [inline]
netdev_sync_lower_features net/core/dev.c:10945 [inline]
__netdev_update_features+0xde7/0x1ef0 net/core/dev.c:11107
netdev_change_features net/core/dev.c:11181 [inline]
netdev_compute_master_upper_features+0x90c/0xb30 net/core/dev.c:13069
__bond_release_one+0x9db/0x11c0 drivers/net/bonding/bond_main.c:2543
do_set_master+0x332/0x720 net/core/rtnetlink.c:3055
do_setlink+0xe7b/0x4670 net/core/rtnetlink.c:3273
rtnl_changelink net/core/rtnetlink.c:3905 [inline]
__rtnl_newlink net/core/rtnetlink.c:4076 [inline]
rtnl_newlink+0x15a3/0x1c30 net/core/rtnetlink.c:4215
rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
__sock_sendmsg net/socket.c:815 [inline]
____sys_sendmsg+0x565/0x870 net/socket.c:2713
___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
__sys_sendmsg net/socket.c:2799 [inline]
__do_sys_sendmsg net/socket.c:2804 [inline]
__se_sys_sendmsg net/socket.c:2802 [inline]
__x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2802
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&dev_instance_lock_key#23){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578
netdev_lock include/linux/netdevice.h:2861 [inline]
netdev_lock_ops include/net/netdev_lock.h:42 [inline]
xsk_bind+0x331/0x11d0 net/xdp/xsk.c:1627
__sys_bind_socket net/socket.c:1945 [inline]
__sys_bind+0x2e9/0x410 net/socket.c:1976
__do_sys_bind net/socket.c:1981 [inline]
__se_sys_bind net/socket.c:1979 [inline]
__x64_sys_bind+0x7a/0x90 net/socket.c:1979
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&xs->mutex){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3181 [inline]
check_prevs_add kernel/locking/lockdep.c:3300 [inline]
validate_chain kernel/locking/lockdep.c:3924 [inline]
__lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5253
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
__mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578
xsk_diag_fill net/xdp/xsk_diag.c:113 [inline]
xsk_diag_dump+0x533/0x1560 net/xdp/xsk_diag.c:166
netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2331
__netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2446
netlink_dump_start include/linux/netlink.h:341 [inline]
xsk_diag_handler_dump+0x1a0/0x250 net/xdp/xsk_diag.c:193
sock_diag_rcv_msg+0x4b0/0x5f0 net/core/sock_diag.c:-1
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
__sock_sendmsg net/socket.c:815 [inline]
sock_write_iter+0x2e4/0x3f0 net/socket.c:1266
do_iter_readv_writev+0x624/0x8d0 fs/read_write.c:-1
vfs_writev+0x34c/0x990 fs/read_write.c:1058
do_writev+0x15a/0x2e0 fs/read_write.c:1104
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&xs->mutex --> &port->pnodes_lock --> &net->xdp.lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&net->xdp.lock);
lock(&port->pnodes_lock);
lock(&net->xdp.lock);
lock(&xs->mutex);
*** DEADLOCK ***
locks held by syz.6.13158/8347: 2, last CPU#0:
#0: ffff88803f078928 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2410
#1: ffff888061732440 (&net->xdp.lock){+.+.}-{4:4}, at: xsk_diag_dump+0x184/0x1560 net/xdp/xsk_diag.c:158
stack backtrace:
CPU: 0 UID: 0 PID: 8347 Comm: syz.6.13158 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2059
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2191
check_prev_add kernel/locking/lockdep.c:3181 [inline]
check_prevs_add kernel/locking/lockdep.c:3300 [inline]
validate_chain kernel/locking/lockdep.c:3924 [inline]
__lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5253
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
__mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578
xsk_diag_fill net/xdp/xsk_diag.c:113 [inline]
xsk_diag_dump+0x533/0x1560 net/xdp/xsk_diag.c:166
netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2331
__netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2446
netlink_dump_start include/linux/netlink.h:341 [inline]
xsk_diag_handler_dump+0x1a0/0x250 net/xdp/xsk_diag.c:193
sock_diag_rcv_msg+0x4b0/0x5f0 net/core/sock_diag.c:-1
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
__sock_sendmsg net/socket.c:815 [inline]
sock_write_iter+0x2e4/0x3f0 net/socket.c:1266
do_iter_readv_writev+0x624/0x8d0 fs/read_write.c:-1
vfs_writev+0x34c/0x990 fs/read_write.c:1058
do_writev+0x15a/0x2e0 fs/read_write.c:1104
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f22bcb6e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f22badc6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f22bcdf5fa0 RCX: 00007f22bcb6e0d9
RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000004
RBP: 00007f22bcc05024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f22bcdf6038 R14: 00007f22bcdf5fa0 R15: 00007ffc199cb668
</TASK>
netlink: 24 bytes leftover after parsing attributes in process `syz.6.13158'.
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2026-08-24 19:47 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2026-08-24 19:47 [syzbot] [bpf?] [net?] possible deadlock in xsk_diag_dump (3) syzbot
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®