------------[ cut here ]------------
WARNING: CPU: 0 PID: 11383 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: 11383 Comm: syz.2.1691 Not tainted 6.12.0-syzkaller #0
Hardware name: ARM-Versatile Express
Call trace: frame pointer underflow
[<819b7fb8>] (dump_backtrace) from [<819b80b4>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:00000000 r6:82623304 r5:00000000 r4:820413b8
[<819b809c>] (show_stack) from [<819d60dc>] (__dump_stack lib/dump_stack.c:94 [inline])
[<819b809c>] (show_stack) from [<819d60dc>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:120)
[<819d6088>] (dump_stack_lvl) from [<819d611c>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
 r5:00000000 r4:82874d18
[<819d6104>] (dump_stack) from [<819b8be0>] (panic+0x120/0x374 kernel/panic.c:354)
[<819b8ac0>] (panic) from [<802426d0>] (check_panic_on_warn kernel/panic.c:243 [inline])
[<819b8ac0>] (panic) from [<802426d0>] (get_taint+0x0/0x1c kernel/panic.c:238)
 r3:8260c604 r2:00000001 r1:82029878 r0:82031344
 r7:8084bbd8
[<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 r7:8209017c r6:df801c64 r5:83678c00 r4:00000000
[<80242940>] (warn_slowpath_fmt) from [<8084bbd8>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:20000113 r9:850b845c r8:848e4840 r7:00000000 r6:818444c4 r5:00000002
 r4:848e4840
[<8084ba9c>] (refcount_warn_saturate) from [<814aa974>] (__refcount_sub_and_test include/linux/refcount.h:275 [inline])
[<8084ba9c>] (refcount_warn_saturate) from [<814aa974>] (__refcount_dec_and_test include/linux/refcount.h:307 [inline])
[<8084ba9c>] (refcount_warn_saturate) from [<814aa974>] (refcount_dec_and_test include/linux/refcount.h:325 [inline])
[<8084ba9c>] (refcount_warn_saturate) from [<814aa974>] (skb_unref include/linux/skbuff.h:1233 [inline])
[<8084ba9c>] (refcount_warn_saturate) from [<814aa974>] (__sk_skb_reason_drop net/core/skbuff.c:1213 [inline])
[<8084ba9c>] (refcount_warn_saturate) from [<814aa974>] (sk_skb_reason_drop+0x1d8/0x248 net/core/skbuff.c:1241)
[<814aa79c>] (sk_skb_reason_drop) from [<818444c4>] (kfree_skb_reason include/linux/skbuff.h:1263 [inline])
[<814aa79c>] (sk_skb_reason_drop) from [<818444c4>] (kfree_skb include/linux/skbuff.h:1272 [inline])
[<814aa79c>] (sk_skb_reason_drop) from [<818444c4>] (j1939_session_skb_drop_old net/can/j1939/transport.c:347 [inline])
[<814aa79c>] (sk_skb_reason_drop) from [<818444c4>] (j1939_xtp_rx_cts_one net/can/j1939/transport.c:1445 [inline])
[<814aa79c>] (sk_skb_reason_drop) from [<818444c4>] (j1939_xtp_rx_cts+0x220/0x3d0 net/can/j1939/transport.c:1484)
 r9:850b845c r8:848e4840 r7:8448d698 r6:00000df2 r5:850b8400 r4:850b8414
[<818442a4>] (j1939_xtp_rx_cts) from [<81845438>] (j1939_tp_cmd_recv net/can/j1939/transport.c:2089 [inline])
[<818442a4>] (j1939_xtp_rx_cts) from [<81845438>] (j1939_tp_recv+0x3f4/0x530 net/can/j1939/transport.c:2161)
 r10:dddd0e88 r9:00000040 r8:8448d690 r7:84953000 r6:84953008 r5:84953000
 r4:85986600
[<81845044>] (j1939_tp_recv) from [<8183eed0>] (j1939_can_recv+0x1e4/0x2dc net/can/j1939/main.c:108)
 r7:84953000 r6:84953008 r5:84953810 r4:85986600
[<8183ecec>] (j1939_can_recv) from [<81834b94>] (deliver net/can/af_can.c:573 [inline])
[<8183ecec>] (j1939_can_recv) from [<81834b94>] (can_rcv_filter+0x9c/0x218 net/can/af_can.c:607)
 r9:00000040 r8:84b386c0 r7:98c80000 r6:85986540 r5:00000001 r4:85030d20
[<81834af8>] (can_rcv_filter) from [<81835610>] (can_receive+0xb4/0xf0 net/can/af_can.c:664)
 r9:00000040 r8:00000000 r7:84b38000 r6:85056980 r5:84760000 r4:85986540
[<8183555c>] (can_receive) from [<818356d0>] (can_rcv+0x84/0xac net/can/af_can.c:688)
 r9:00000040 r8:00000001 r7:00000000 r6:00000000 r5:8183564c r4:85986540
[<8183564c>] (can_rcv) from [<814cc17c>] (__netif_receive_skb_one_core+0x5c/0x80 net/core/dev.c:5672)
 r5:8183564c r4:84b38000
[<814cc120>] (__netif_receive_skb_one_core) from [<814cc1e8>] (__netif_receive_skb+0x18/0x5c net/core/dev.c:5785)
 r5:dddd0f70 r4:85986540
[<814cc1d0>] (__netif_receive_skb) from [<814cc4f0>] (process_backlog+0xa0/0x17c net/core/dev.c:6117)
 r5:dddd0f70 r4:85986540
[<814cc450>] (process_backlog) from [<814cd3f0>] (__napi_poll+0x34/0x240 net/core/dev.c:6877)
 r10:dddd0e80 r9:dddd10c0 r8:df801ea0 r7:df801e9b r6:00000040 r5:dddd0f70
 r4:00000001
[<814cd3bc>] (__napi_poll) from [<814cdc64>] (napi_poll net/core/dev.c:6946 [inline])
[<814cd3bc>] (__napi_poll) from [<814cdc64>] (net_rx_action+0x358/0x440 net/core/dev.c:7068)
 r9:dddd10c0 r8:df801ea0 r7:0000012c r6:0001e106 r5:dddd0f70 r4:00000000
[<814cd90c>] (net_rx_action) from [<8024ba68>] (handle_softirqs+0x158/0x464 kernel/softirq.c:554)
 r10:00000008 r9:83678c00 r8:00000101 r7:00400040 r6:00000003 r5:00000004
 r4:8260408c
[<8024b910>] (handle_softirqs) from [<8024bed0>] (__do_softirq kernel/softirq.c:588 [inline])
[<8024b910>] (handle_softirqs) from [<8024bed0>] (invoke_softirq kernel/softirq.c:428 [inline])
[<8024b910>] (handle_softirqs) from [<8024bed0>] (__irq_exit_rcu+0x110/0x1d0 kernel/softirq.c:655)
 r10:00000001 r9:83678c00 r8:00000000 r7:dfb71d68 r6:821e34dc r5:82223e4c
 r4:83678c00
[<8024bdc0>] (__irq_exit_rcu) from [<8024c248>] (irq_exit+0x10/0x18 kernel/softirq.c:683)
 r5:82223e4c r4:824bca74
[<8024c238>] (irq_exit) from [<819d6ab8>] (generic_handle_arch_irq+0x7c/0x80 kernel/irq/handle.c:240)
[<819d6a3c>] (generic_handle_arch_irq) from [<8198744c>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40)
 r9:83678c00 r8:82e3b000 r7:dfb71d9c r6:ffffffff r5:20000113 r4:8027e404
[<81987430>] (call_with_stack) from [<80200bcc>] (__irq_svc+0x8c/0xbc arch/arm/kernel/entry-armv.S:227)
Exception stack(0xdfb71d68 to 0xdfb71db0)
1d60:                   00000001 820413b8 00000001 83678c00 00000000 dddd0180
1d80: 819da440 a3e9df98 82e3b000 83678c00 00000001 dfb71dfc dfb71da8 dfb71db8
1da0: 819e35bc 8027e404 20000113 ffffffff
[<8027e378>] (finish_task_switch) from [<819da440>] (context_switch kernel/sched/core.c:5372 [inline])
[<8027e378>] (finish_task_switch) from [<819da440>] (__schedule+0x430/0xc30 kernel/sched/core.c:6756)
 r10:84052cc0 r9:00000000 r8:84052a00 r7:a3e9df98 r6:dddd0180 r5:83678c00
 r4:82e36c00
[<819da010>] (__schedule) from [<819dac6c>] (__schedule_loop kernel/sched/core.c:6833 [inline])
[<819da010>] (__schedule) from [<819dac6c>] (schedule+0x2c/0xfc kernel/sched/core.c:6848)
 r10:00000109 r9:83678c00 r8:00000000 r7:83678c00 r6:00002001 r5:83678c00
 r4:83678c00
[<819dac40>] (schedule) from [<819e23b4>] (do_nanosleep+0x90/0x15c kernel/time/hrtimer.c:2079)
 r5:83678c00 r4:dfb71ee8
[<819e2324>] (do_nanosleep) from [<80308ee0>] (hrtimer_nanosleep+0xa8/0x124 kernel/time/hrtimer.c:2126)
 r8:00000000 r7:83678c00 r6:00000001 r5:00989680 r4:00000000
[<80308e38>] (hrtimer_nanosleep) from [<803130a4>] (common_nsleep+0x5c/0x6c kernel/time/posix-timers.c:1356)
 r8:7e8137c4 r7:83678c00 r6:00000000 r5:00000000 r4:3b9aca00
[<80313048>] (common_nsleep) from [<80315aa4>] (__do_sys_clock_nanosleep_time32 kernel/time/posix-timers.c:1430 [inline])
[<80313048>] (common_nsleep) from [<80315aa4>] (sys_clock_nanosleep_time32+0xf8/0x154 kernel/time/posix-timers.c:1407)
 r5:81a0473c r4:00000000
[<803159ac>] (sys_clock_nanosleep_time32) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67)
Exception stack(0xdfb71fa8 to 0xdfb71ff0)
1fa0:                   00000000 7e8137c4 00000000 00000000 7e8137cc 7e8137c4
1fc0: 00000000 7e8137c4 00000000 00000109 00000000 00270000 001761ea 00000000
1fe0: 00000000 7e8137c0 000d8998 00160794
 r8:8020029c r7:00000109 r6:00000000 r5:7e8137c4 r4:00000000
Rebooting in 86400 seconds..