------------[ cut here ]------------
WARNING: CPU: 0 PID: 3791 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: 3791 Comm: kworker/0:4 Not tainted 6.11.0-syzkaller #0
Hardware name: ARM-Versatile Express
Workqueue: events nsim_dev_trap_report_work
Call trace: frame pointer underflow
[<8197d658>] (dump_backtrace) from [<8197d754>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:00000000 r6:826228c4 r5:00000000 r4:82034f2c
[<8197d73c>] (show_stack) from [<8199b3f8>] (__dump_stack lib/dump_stack.c:93 [inline])
[<8197d73c>] (show_stack) from [<8199b3f8>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:119)
[<8199b3a4>] (dump_stack_lvl) from [<8199b438>] (dump_stack+0x18/0x1c lib/dump_stack.c:128)
 r5:00000000 r4:8286ed18
[<8199b420>] (dump_stack) from [<8197e1fc>] (panic+0x120/0x368 kernel/panic.c:354)
[<8197e0dc>] (panic) from [<802421d4>] (check_panic_on_warn kernel/panic.c:243 [inline])
[<8197e0dc>] (panic) from [<802421d4>] (get_taint+0x0/0x1c kernel/panic.c:238)
 r3:8260c5c4 r2:00000001 r1:8201d760 r0:8202552c
 r7:808309e0
[<80242160>] (check_panic_on_warn) from [<80242328>] (__warn+0x7c/0x180 kernel/panic.c:741)
[<802422ac>] (__warn) from [<80242614>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:774)
 r8:00000009 r7:82083a1c r6:df801c94 r5:83e19800 r4:00000000
[<80242430>] (warn_slowpath_fmt) from [<808309e0>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:20000113 r9:8531d45c r8:84234300 r7:00000000 r6:8180dd24 r5:00000002
 r4:84234300
[<808308a4>] (refcount_warn_saturate) from [<8147e1bc>] (__refcount_sub_and_test include/linux/refcount.h:275 [inline])
[<808308a4>] (refcount_warn_saturate) from [<8147e1bc>] (__refcount_dec_and_test include/linux/refcount.h:307 [inline])
[<808308a4>] (refcount_warn_saturate) from [<8147e1bc>] (refcount_dec_and_test include/linux/refcount.h:325 [inline])
[<808308a4>] (refcount_warn_saturate) from [<8147e1bc>] (skb_unref include/linux/skbuff.h:1232 [inline])
[<808308a4>] (refcount_warn_saturate) from [<8147e1bc>] (__sk_skb_reason_drop net/core/skbuff.c:1213 [inline])
[<808308a4>] (refcount_warn_saturate) from [<8147e1bc>] (sk_skb_reason_drop+0x1d8/0x248 net/core/skbuff.c:1241)
[<8147dfe4>] (sk_skb_reason_drop) from [<8180dd24>] (kfree_skb_reason include/linux/skbuff.h:1262 [inline])
[<8147dfe4>] (sk_skb_reason_drop) from [<8180dd24>] (kfree_skb include/linux/skbuff.h:1271 [inline])
[<8147dfe4>] (sk_skb_reason_drop) from [<8180dd24>] (j1939_session_skb_drop_old net/can/j1939/transport.c:347 [inline])
[<8147dfe4>] (sk_skb_reason_drop) from [<8180dd24>] (j1939_xtp_rx_cts_one net/can/j1939/transport.c:1445 [inline])
[<8147dfe4>] (sk_skb_reason_drop) from [<8180dd24>] (j1939_xtp_rx_cts+0x220/0x3d0 net/can/j1939/transport.c:1484)
 r9:8531d45c r8:84234300 r7:853e2918 r6:00000df2 r5:8531d400 r4:8531d414
[<8180db04>] (j1939_xtp_rx_cts) from [<8180ec98>] (j1939_tp_cmd_recv net/can/j1939/transport.c:2089 [inline])
[<8180db04>] (j1939_xtp_rx_cts) from [<8180ec98>] (j1939_tp_recv+0x3f4/0x530 net/can/j1939/transport.c:2161)
 r10:dddd0ec8 r9:00000040 r8:853e2910 r7:85373000 r6:85373008 r5:85373000
 r4:843c6a80
[<8180e8a4>] (j1939_tp_recv) from [<81808730>] (j1939_can_recv+0x1e4/0x2dc net/can/j1939/main.c:108)
 r7:85373000 r6:85373008 r5:85373810 r4:843c6a80
[<8180854c>] (j1939_can_recv) from [<817fe4fc>] (deliver net/can/af_can.c:572 [inline])
[<8180854c>] (j1939_can_recv) from [<817fe4fc>] (can_rcv_filter+0x9c/0x218 net/can/af_can.c:606)
 r9:00000040 r8:8490c6a0 r7:98c80000 r6:843c6cc0 r5:00000001 r4:8520ba20
[<817fe460>] (can_rcv_filter) from [<817feea0>] (can_receive+0xb4/0xf0 net/can/af_can.c:663)
 r9:00000040 r8:00000000 r7:8490c000 r6:84d16b00 r5:84891a00 r4:843c6cc0
[<817fedec>] (can_receive) from [<817fef60>] (can_rcv+0x84/0xac net/can/af_can.c:687)
 r9:00000040 r8:00000002 r7:00000000 r6:00000000 r5:817feedc r4:843c6cc0
[<817feedc>] (can_rcv) from [<8149f034>] (__netif_receive_skb_one_core+0x5c/0x80 net/core/dev.c:5662)
 r5:817feedc r4:8490c000
[<8149efd8>] (__netif_receive_skb_one_core) from [<8149f0a0>] (__netif_receive_skb+0x18/0x5c net/core/dev.c:5775)
 r5:dddd0fb0 r4:843c6cc0
[<8149f088>] (__netif_receive_skb) from [<8149f390>] (process_backlog+0x88/0x15c net/core/dev.c:6107)
 r5:dddd0fb0 r4:843c6cc0
[<8149f308>] (process_backlog) from [<814a0294>] (__napi_poll+0x34/0x240 net/core/dev.c:6771)
 r10:dddd0ec0 r9:dddd1100 r8:df801ed0 r7:df801ecb r6:00000040 r5:dddd0fb0
 r4:00000001
[<814a0260>] (__napi_poll) from [<814a0acc>] (napi_poll net/core/dev.c:6840 [inline])
[<814a0260>] (__napi_poll) from [<814a0acc>] (net_rx_action+0x338/0x420 net/core/dev.c:6962)
 r9:dddd1100 r8:df801ed0 r7:0000012c r6:00012feb r5:dddd0fb0 r4:00000000
[<814a0794>] (net_rx_action) from [<8024b5d8>] (handle_softirqs+0x15c/0x468 kernel/softirq.c:554)
 r10:00000002 r9:83e19800 r8:00000102 r7:04208060 r6:00000003 r5:00000002
 r4:8260408c
[<8024b47c>] (handle_softirqs) from [<802012d0>] (__do_softirq+0x14/0x18 kernel/softirq.c:588)
 r10:85166d00 r9:85166dfc r8:00000040 r7:85169980 r6:81b8f4e8 r5:00000002
 r4:60000113
[<802012bc>] (__do_softirq) from [<80208800>] (____do_softirq+0x10/0x14 arch/arm/kernel/irq.c:77)
[<802087f0>] (____do_softirq) from [<8194d0f8>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40)
[<8194d0dc>] (call_with_stack) from [<8020883c>] (do_softirq_own_stack+0x38/0x3c arch/arm/kernel/irq.c:82)
[<80208804>] (do_softirq_own_stack) from [<8024baf0>] (do_softirq kernel/softirq.c:455 [inline])
[<80208804>] (do_softirq_own_stack) from [<8024baf0>] (do_softirq+0x5c/0x64 kernel/softirq.c:442)
[<8024ba94>] (do_softirq) from [<8024bbc4>] (__local_bh_enable_ip+0xcc/0xd0 kernel/softirq.c:382)
 r5:00000002 r4:83e19800
[<8024baf8>] (__local_bh_enable_ip) from [<819a8418>] (__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline])
[<8024baf8>] (__local_bh_enable_ip) from [<819a8418>] (_raw_spin_unlock_bh+0x34/0x38 kernel/locking/spinlock.c:210)
 r5:851693c0 r4:843c60c0
[<819a83e4>] (_raw_spin_unlock_bh) from [<80d857fc>] (spin_unlock_bh include/linux/spinlock.h:396 [inline])
[<819a83e4>] (_raw_spin_unlock_bh) from [<80d857fc>] (nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline])
[<819a83e4>] (_raw_spin_unlock_bh) from [<80d857fc>] (nsim_dev_trap_report_work+0x29c/0x33c drivers/net/netdevsim/dev.c:850)
[<80d85560>] (nsim_dev_trap_report_work) from [<80265ef4>] (process_one_work+0x1b4/0x4f4 kernel/workqueue.c:3231)
 r10:82c16005 r9:83e19800 r8:00800000 r7:dddcff40 r6:82c16000 r5:85169980
 r4:85252100
[<80265d40>] (process_one_work) from [<80266ad8>] (process_scheduled_works kernel/workqueue.c:3312 [inline])
[<80265d40>] (process_one_work) from [<80266ad8>] (worker_thread+0x1ec/0x3bc kernel/workqueue.c:3393)
 r10:83e19800 r9:8525212c r8:61c88647 r7:dddcff60 r6:82604d40 r5:dddcff40
 r4:85252100
[<802668ec>] (worker_thread) from [<8026faf4>] (kthread+0x104/0x134 kernel/kthread.c:389)
 r10:00000000 r9:df921e78 r8:85280200 r7:85252100 r6:802668ec r5:83e19800
 r4:85256980
[<8026f9f0>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137)
Exception stack(0xdfdcdfb0 to 0xdfdcdff8)
dfa0:                                     00000000 00000000 00000000 00000000
dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:8026f9f0 r4:85256980
Rebooting in 86400 seconds..