------------[ cut here ]------------
WARNING: CPU: 0 PID: 5174 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: 0 UID: 0 PID: 5174 Comm: syz.0.406 Not tainted 6.12.0-syzkaller #0
Hardware name: ARM-Versatile Express
Call trace: 
[<819acd78>] (dump_backtrace) from [<819ace74>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:00000000 r6:82623184 r5:00000000 r4:82040a28
[<819ace5c>] (show_stack) from [<819cae9c>] (__dump_stack lib/dump_stack.c:94 [inline])
[<819ace5c>] (show_stack) from [<819cae9c>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:120)
[<819cae48>] (dump_stack_lvl) from [<819caedc>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
 r5:00000000 r4:82871d18
[<819caec4>] (dump_stack) from [<819ad9a0>] (panic+0x120/0x374 kernel/panic.c:354)
[<819ad880>] (panic) from [<802426d0>] (check_panic_on_warn kernel/panic.c:243 [inline])
[<819ad880>] (panic) from [<802426d0>] (get_taint+0x0/0x1c kernel/panic.c:238)
 r3:8260c604 r2:00000001 r1:82028f94 r0:82030a60
 r7:80847a50
[<8024265c>] (check_panic_on_warn) from [<80242834>] (__warn+0x80/0x188 kernel/panic.c:748)
[<802427b4>] (__warn) from [<80242b24>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:783)
 r8:00000009 r7:8208f6ec r6:ea8c5d6c r5:8471bc00 r4:00000000
[<80242940>] (warn_slowpath_fmt) from [<80847a50>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:000001b4 r9:84bc7e80 r8:0000006c r7:00000000 r6:8183a37c r5:00000002
 r4:852749c0
[<80847914>] (refcount_warn_saturate) from [<814abdc8>] (__refcount_sub_and_test include/linux/refcount.h:275 [inline])
[<80847914>] (refcount_warn_saturate) from [<814abdc8>] (__refcount_dec_and_test include/linux/refcount.h:307 [inline])
[<80847914>] (refcount_warn_saturate) from [<814abdc8>] (refcount_dec_and_test include/linux/refcount.h:325 [inline])
[<80847914>] (refcount_warn_saturate) from [<814abdc8>] (skb_unref include/linux/skbuff.h:1232 [inline])
[<80847914>] (refcount_warn_saturate) from [<814abdc8>] (__sk_skb_reason_drop net/core/skbuff.c:1213 [inline])
[<80847914>] (refcount_warn_saturate) from [<814abdc8>] (sk_skb_reason_drop+0x1d8/0x248 net/core/skbuff.c:1241)
[<814abbf0>] (sk_skb_reason_drop) from [<8183a37c>] (kfree_skb_reason include/linux/skbuff.h:1262 [inline])
[<814abbf0>] (sk_skb_reason_drop) from [<8183a37c>] (kfree_skb include/linux/skbuff.h:1271 [inline])
[<814abbf0>] (sk_skb_reason_drop) from [<8183a37c>] (j1939_session_destroy+0x78/0x200 net/can/j1939/transport.c:282)
 r9:84bc7e80 r8:0000006c r7:84bc7e84 r6:8502fe50 r5:8502fe00 r4:852749c0
[<8183a304>] (j1939_session_destroy) from [<8183b698>] (__j1939_session_release net/can/j1939/transport.c:294 [inline])
[<8183a304>] (j1939_session_destroy) from [<8183b698>] (kref_put include/linux/kref.h:65 [inline])
[<8183a304>] (j1939_session_destroy) from [<8183b698>] (j1939_session_put+0x54/0x58 net/can/j1939/transport.c:299)
 r6:84bc7e78 r5:84bc7e78 r4:84bc7e78
[<8183b644>] (j1939_session_put) from [<81838758>] (j1939_sk_queue_drop_all+0x7c/0xc4 net/can/j1939/socket.c:144)
[<818386dc>] (j1939_sk_queue_drop_all) from [<81838998>] (j1939_sk_release+0x1f8/0x200 net/can/j1939/socket.c:642)
 r9:8471bc00 r8:82caf790 r7:84bc7e74 r6:848b9000 r5:8321ac80 r4:84bc7c00
[<818387a0>] (j1939_sk_release) from [<814956f4>] (__sock_release+0x44/0xbc net/socket.c:640)
 r8:82caf790 r7:00000000 r6:81c7f1d4 r5:8321ad80 r4:8321ac80
[<814956b0>] (__sock_release) from [<81495784>] (sock_close+0x18/0x20 net/socket.c:1408)
 r7:8321ad00 r6:8309b088 r5:082e0003 r4:84454cc0
[<8149576c>] (sock_close) from [<8051b58c>] (__fput+0xdc/0x2f0 fs/file_table.c:450)
[<8051b4b0>] (__fput) from [<8051b828>] (____fput+0x14/0x18 fs/file_table.c:478)
 r9:8471bc00 r8:82872694 r7:8471bc00 r6:8471c484 r5:8471c454 r4:844541e8
[<8051b814>] (____fput) from [<8026d41c>] (task_work_run+0x90/0xb8 kernel/task_work.c:239)
[<8026d38c>] (task_work_run) from [<8020be00>] (resume_user_mode_work include/linux/resume_user_mode.h:50 [inline])
[<8026d38c>] (task_work_run) from [<8020be00>] (do_work_pending+0x448/0x4f8 arch/arm/kernel/signal.c:631)
 r9:8471bc00 r8:8020029c r7:000001b4 r6:8020029c r5:ea8c5fb0 r4:8471bc00
[<8020b9b8>] (do_work_pending) from [<80200088>] (slow_work_pending+0xc/0x24)
Exception stack(0xea8c5fb0 to 0xea8c5ff8)
5fa0:                                     00000000 ffffffff 00000000 00000000
5fc0: 00000000 00000000 002862f0 000001b4 00000000 00006364 003d0f00 76b990bc
5fe0: 76b98ec0 76b98eb0 00018af0 00133450 60000010 00000004
 r10:000001b4 r9:8471bc00 r8:8020029c r7:000001b4 r6:002862f0 r5:00000000
 r4:00000000
Rebooting in 86400 seconds..