netlink: 28 bytes leftover after parsing attributes in process `syz.1.181'.
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4851 at lib/refcount.c:28 refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28
refcount_t: underflow; use-after-free.
Modules linked in:
Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 1 UID: 0 PID: 4851 Comm: syz.1.181 Not tainted 6.11.0-syzkaller #0
Hardware name: ARM-Versatile Express
Call trace: 
[<81985f40>] (dump_backtrace) from [<8198603c>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:00000000 r6:826228c4 r5:00000000 r4:82035a48
[<81986024>] (show_stack) from [<819a431c>] (__dump_stack lib/dump_stack.c:93 [inline])
[<81986024>] (show_stack) from [<819a431c>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:119)
[<819a42c8>] (dump_stack_lvl) from [<819a435c>] (dump_stack+0x18/0x1c lib/dump_stack.c:128)
 r5:00000000 r4:8286dd18
[<819a4344>] (dump_stack) from [<81986b68>] (panic+0x120/0x370 kernel/panic.c:354)
[<81986a48>] (panic) from [<802421dc>] (check_panic_on_warn kernel/panic.c:243 [inline])
[<81986a48>] (panic) from [<802421dc>] (get_taint+0x0/0x1c kernel/panic.c:238)
 r3:8260c5c4 r2:00000001 r1:8201e0ec r0:82025eb8
 r7:808348c0
[<80242168>] (check_panic_on_warn) from [<8024233c>] (__warn+0x80/0x188 kernel/panic.c:748)
[<802422bc>] (__warn) from [<8024262c>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:783)
 r8:00000009 r7:82084ad8 r6:dfb11854 r5:84b60c00 r4:00000000
[<80242448>] (warn_slowpath_fmt) from [<808348c0>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:84c7aa00 r9:0000006c r8:8515781c r7:00000000 r6:81813f34 r5:00000002
 r4:84a130c0
[<80834784>] (refcount_warn_saturate) from [<814867d0>] (__refcount_sub_and_test include/linux/refcount.h:275 [inline])
[<80834784>] (refcount_warn_saturate) from [<814867d0>] (__refcount_dec_and_test include/linux/refcount.h:307 [inline])
[<80834784>] (refcount_warn_saturate) from [<814867d0>] (refcount_dec_and_test include/linux/refcount.h:325 [inline])
[<80834784>] (refcount_warn_saturate) from [<814867d0>] (skb_unref include/linux/skbuff.h:1232 [inline])
[<80834784>] (refcount_warn_saturate) from [<814867d0>] (__sk_skb_reason_drop net/core/skbuff.c:1213 [inline])
[<80834784>] (refcount_warn_saturate) from [<814867d0>] (sk_skb_reason_drop+0x1d8/0x248 net/core/skbuff.c:1241)
[<814865f8>] (sk_skb_reason_drop) from [<81813f34>] (kfree_skb_reason include/linux/skbuff.h:1262 [inline])
[<814865f8>] (sk_skb_reason_drop) from [<81813f34>] (kfree_skb include/linux/skbuff.h:1271 [inline])
[<814865f8>] (sk_skb_reason_drop) from [<81813f34>] (j1939_session_destroy+0x78/0x200 net/can/j1939/transport.c:282)
 r9:0000006c r8:8515781c r7:00000000 r6:84c7aa50 r5:84c7aa00 r4:84a130c0
[<81813ebc>] (j1939_session_destroy) from [<81817918>] (__j1939_session_release net/can/j1939/transport.c:294 [inline])
[<81813ebc>] (j1939_session_destroy) from [<81817918>] (kref_put include/linux/kref.h:65 [inline])
[<81813ebc>] (j1939_session_destroy) from [<81817918>] (j1939_session_put net/can/j1939/transport.c:299 [inline])
[<81813ebc>] (j1939_session_destroy) from [<81817918>] (j1939_session_deactivate_locked net/can/j1939/transport.c:1086 [inline])
[<81813ebc>] (j1939_session_destroy) from [<81817918>] (j1939_session_deactivate_locked net/can/j1939/transport.c:1074 [inline])
[<81813ebc>] (j1939_session_destroy) from [<81817918>] (j1939_cancel_active_session+0x1f0/0x1fc net/can/j1939/transport.c:2211)
 r6:85157814 r5:84c7aa04 r4:85157810
[<81817728>] (j1939_cancel_active_session) from [<81810c74>] (j1939_netdev_notify+0x108/0x150 net/can/j1939/main.c:376)
 r10:84b60c00 r9:00000000 r8:ffffffcd r7:00000001 r6:85157000 r5:00000002
 r4:85157810
[<81810b6c>] (j1939_netdev_notify) from [<8027149c>] (notifier_call_chain+0x74/0x1ac kernel/notifier.c:93)
 r7:00000001 r6:827e6e64 r5:827e6e84 r4:81810b6c
[<80271428>] (notifier_call_chain) from [<802716b8>] (raw_notifier_call_chain+0x20/0x28 kernel/notifier.c:461)
 r10:821f0774 r9:00000000 r8:85410000 r7:00000001 r6:84b50d00 r5:00000002
 r4:dfb119dc
[<80271698>] (raw_notifier_call_chain) from [<814a1508>] (call_netdevice_notifiers_info+0x54/0xa0 net/core/dev.c:1996)
[<814a14b4>] (call_netdevice_notifiers_info) from [<814a19a4>] (call_netdevice_notifiers_extack net/core/dev.c:2034 [inline])
[<814a14b4>] (call_netdevice_notifiers_info) from [<814a19a4>] (call_netdevice_notifiers net/core/dev.c:2048 [inline])
[<814a14b4>] (call_netdevice_notifiers_info) from [<814a19a4>] (dev_close_many+0xfc/0x150 net/core/dev.c:1589)
 r6:dfb11a48 r5:dfb1192c r4:8541011c
[<814a18a8>] (dev_close_many) from [<814acd08>] (unregister_netdevice_many_notify+0x194/0x9c0 net/core/dev.c:11373)
 r9:00000001 r8:dfb11a48 r7:8541011c r6:dfb11ab0 r5:dfb11a48 r4:dfb1199c
[<814acb74>] (unregister_netdevice_many_notify) from [<814bc8e4>] (rtnl_delete_link net/core/rtnetlink.c:3252 [inline])
[<814acb74>] (unregister_netdevice_many_notify) from [<814bc8e4>] (rtnl_dellink+0x134/0x354 net/core/rtnetlink.c:3304)
 r10:00000001 r9:00000000 r8:00000050 r7:84b50d00 r6:ffffffff r5:849529c0
 r4:84a8b680
[<814bc7b0>] (rtnl_dellink) from [<814bb02c>] (rtnetlink_rcv_msg+0x138/0x334 net/core/rtnetlink.c:6646)
 r9:00000000 r8:8291ebd8 r7:849529c0 r6:8291ebd8 r5:00000001 r4:84a8b680
[<814baef4>] (rtnetlink_rcv_msg) from [<81594e18>] (netlink_rcv_skb+0xc0/0x120 net/netlink/af_netlink.c:2550)
 r10:00000000 r9:00000000 r8:84b50d00 r7:0000003c r6:84a8b680 r5:814baef4
 r4:849529c0
[<81594d58>] (netlink_rcv_skb) from [<814b99cc>] (rtnetlink_rcv+0x18/0x1c net/core/rtnetlink.c:6664)
 r7:849529c0 r6:84c5f880 r5:0000003c r4:84d15800
[<814b99b4>] (rtnetlink_rcv) from [<81594600>] (netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline])
[<814b99b4>] (rtnetlink_rcv) from [<81594600>] (netlink_unicast+0x19c/0x29c net/netlink/af_netlink.c:1357)
[<81594464>] (netlink_unicast) from [<815948dc>] (netlink_sendmsg+0x1dc/0x43c net/netlink/af_netlink.c:1901)
 r9:00000000 r8:00000000 r7:8514d000 r6:0000003c r5:849529c0 r4:dfb11f38
[<81594700>] (netlink_sendmsg) from [<8147147c>] (sock_sendmsg_nosec net/socket.c:730 [inline])
[<81594700>] (netlink_sendmsg) from [<8147147c>] (__sock_sendmsg+0x44/0x78 net/socket.c:745)
 r10:00004000 r9:dfb11dd4 r8:dfb11dd4 r7:00000000 r6:831ec780 r5:dfb11f38
 r4:00000000
[<81471438>] (__sock_sendmsg) from [<81472480>] (____sys_sendmsg+0x2ac/0x2cc net/socket.c:2603)
 r7:00000000 r6:00000000 r5:831ec780 r4:dfb11f38
[<814721d4>] (____sys_sendmsg) from [<814743ec>] (___sys_sendmsg+0x9c/0xd0 net/socket.c:2657)
 r10:dfb11e34 r9:20000140 r8:00004000 r7:00000000 r6:831ec780 r5:dfb11f38
 r4:00000000
[<81474350>] (___sys_sendmsg) from [<81474904>] (__sys_sendmsg net/socket.c:2686 [inline])
[<81474350>] (___sys_sendmsg) from [<81474904>] (__do_sys_sendmsg net/socket.c:2695 [inline])
[<81474350>] (___sys_sendmsg) from [<81474904>] (sys_sendmsg+0x78/0xbc net/socket.c:2693)
 r10:00000128 r9:84b60c00 r8:8020029c r7:00004000 r6:20000140 r5:831ec780
 r4:00000000
[<8147488c>] (sys_sendmsg) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67)
Exception stack(0xdfb11fa8 to 0xdfb11ff0)
1fa0:                   00000000 00000000 00000006 20000140 00004000 00000000
1fc0: 00000000 00000000 002862f0 00000128 00000000 00006364 003d0f00 76b240bc
1fe0: 76b23ec0 76b23eb0 000189d0 00132da0
 r7:00000128 r6:002862f0 r5:00000000 r4:00000000
Rebooting in 86400 seconds..