netlink: 40 bytes leftover after parsing attributes in process `syz.3.1035'. ===================================== WARNING: bad unlock balance detected! 6.15.0-rc1-next-20250408-syzkaller #0 Not tainted ------------------------------------- syz.3.1035/9307 is trying to release lock (&dev_instance_lock_key) at: [] netdev_unlock include/linux/netdevice.h:2756 [inline] [] netdev_unlock_ops include/net/netdev_lock.h:48 [inline] [] do_setlink+0xc26/0x43a0 net/core/rtnetlink.c:3406 but there are no more locks to release! other info that might help us debug this: 1 lock held by syz.3.1035/9307: #0: ffffffff90100308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff90100308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff90100308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd68/0x1fe0 net/core/rtnetlink.c:4067 stack backtrace: CPU: 1 UID: 0 PID: 9307 Comm: syz.3.1035 Not tainted 6.15.0-rc1-next-20250408-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_unlock_imbalance_bug+0x185/0x1a0 kernel/locking/lockdep.c:5296 __lock_release kernel/locking/lockdep.c:5535 [inline] lock_release+0x1ed/0x3e0 kernel/locking/lockdep.c:5887 __mutex_unlock_slowpath+0xee/0x800 kernel/locking/mutex.c:907 netdev_unlock include/linux/netdevice.h:2756 [inline] netdev_unlock_ops include/net/netdev_lock.h:48 [inline] do_setlink+0xc26/0x43a0 net/core/rtnetlink.c:3406 rtnl_changelink net/core/rtnetlink.c:3772 [inline] __rtnl_newlink net/core/rtnetlink.c:3931 [inline] rtnl_newlink+0x17e2/0x1fe0 net/core/rtnetlink.c:4068 rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:727 ____sys_sendmsg+0x523/0x860 net/socket.c:2566 ___sys_sendmsg net/socket.c:2620 [inline] __sys_sendmsg+0x271/0x360 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8428f8d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8429eab038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f84291a5fa0 RCX: 00007f8428f8d169 RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000003 RBP: 00007f842900e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f84291a5fa0 R15: 00007ffd4e433e28