------------[ cut here ]------------
WARNING: CPU: 1 PID: 8967 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: 8967 Comm: syz.2.1212 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:df805c64 r5:84840c00 r4:00000000
[<80242940>] (warn_slowpath_fmt) from [<8084bbd8>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:20000113 r9:8a31995c r8:8a138300 r7:00000000 r6:818444c4 r5:00000002
 r4:8a138300
[<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)
 r9:8a31995c r8:8a138300 r7:850af218 r6:00000df2 r5:8a319900 r4:8a319914
[<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:ddde4e88 r9:00000040 r8:850af210 r7:8b0f4000 r6:8b0f4008 r5:8b0f4000
 r4:85250000
[<81845044>] (j1939_tp_recv) from [<8183eed0>] (j1939_can_recv+0x1e4/0x2dc net/can/j1939/main.c:108)
 r7:8b0f4000 r6:8b0f4008 r5:8b0f4810 r4:85250000
[<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 r8:851606e0 r7:98c80000 r6:85250240 r5:00000001 r4:84b0c390
[<81834af8>] (can_rcv_filter) from [<81835610>] (can_receive+0xb4/0xf0 net/can/af_can.c:664)
 r9:00000040 r8:00000000 r7:85160000 r6:84fcbcc0 r5:84a9c240 r4:85250240
[<8183555c>] (can_receive) from [<818356d0>] (can_rcv+0x84/0xac net/can/af_can.c:688)
 r9:00000040 r8:00000002 r7:00000000 r6:00000000 r5:8183564c r4:85250240
[<8183564c>] (can_rcv) from [<814cc17c>] (__netif_receive_skb_one_core+0x5c/0x80 net/core/dev.c:5672)
 r5:8183564c r4:85160000
[<814cc120>] (__netif_receive_skb_one_core) from [<814cc1e8>] (__netif_receive_skb+0x18/0x5c net/core/dev.c:5785)
 r5:ddde4f70 r4:85250240
[<814cc1d0>] (__netif_receive_skb) from [<814cc4f0>] (process_backlog+0xa0/0x17c net/core/dev.c:6117)
 r5:ddde4f70 r4:85250240
[<814cc450>] (process_backlog) from [<814cd3f0>] (__napi_poll+0x34/0x240 net/core/dev.c:6877)
 r10:ddde4e80 r9:ddde50c0 r8:df805ea0 r7:df805e9b r6:00000040 r5:ddde4f70
 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:ddde50c0 r8:df805ea0 r7:0000012c r6:000141b8 r5:ddde4f70 r4:00000000
[<814cd90c>] (net_rx_action) from [<8024ba68>] (handle_softirqs+0x158/0x464 kernel/softirq.c:554)
 r10:00000008 r9:84840c00 r8:00000100 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)
 r10:00000128 r9:84840c00 r8:00000000 r7:dfa29cf8 r6:821e34dc r5:82223e4c
 r4:84840c00
[<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)
 r9:84840c00 r8:00006364 r7:dfa29d2c r6:ffffffff r5:60000013 r4:80203298
[<81987430>] (call_with_stack) from [<80200bcc>] (__irq_svc+0x8c/0xbc arch/arm/kernel/entry-armv.S:227)
Exception stack(0xdfa29cf8 to 0xdfa29d40)
9ce0:                                                       00000001 84840de0
9d00: 00000000 00000001 84840c00 dfa29e78 dfa29d70 b5403587 00006364 00000000
9d20: 00000128 dfa29d64 dfa29d30 dfa29d48 80203220 80203298 60000013 ffffffff
[<80203240>] (vfp_preserve_user_clear_hwstate) from [<8020b498>] (preserve_vfp_context+0x4c/0xc4 arch/arm/kernel/signal.c:111)
 r7:b5403587 r6:00000000 r5:84841420 r4:76b79ca0
[<8020b44c>] (preserve_vfp_context) from [<8020b88c>] (setup_sigframe+0x16c/0x1c4 arch/arm/kernel/signal.c:293)
 r5:84841420 r4:76b79bb8
[<8020b720>] (setup_sigframe) from [<8020bdac>] (setup_rt_frame arch/arm/kernel/signal.c:482 [inline])
[<8020b720>] (setup_sigframe) from [<8020bdac>] (handle_signal arch/arm/kernel/signal.c:516 [inline])
[<8020b720>] (setup_sigframe) from [<8020bdac>] (do_signal arch/arm/kernel/signal.c:589 [inline])
[<8020b720>] (setup_sigframe) from [<8020bdac>] (do_work_pending+0x3f4/0x4f8 arch/arm/kernel/signal.c:618)
 r10:b5403587 r9:76b79bb8 r8:00000000 r7:84841420 r6:76b79b38 r5:dfa29fb0
 r4:84840c00
[<8020b9b8>] (do_work_pending) from [<80200088>] (slow_work_pending+0xc/0x24)
Exception stack(0xdfa29fb0 to 0xdfa29ff8)
9fa0:                                     00012bd3 20000180 00000000 00000000
9fc0: 00000000 00000000 002862f0 00000128 00000000 00006364 003d0f00 76b7a0bc
9fe0: 76b79ec0 76b79eb0 00018af0 00133450 60000010 00000153
 r10:000000ad r9:84840c00 r8:00000000 r7:000000ad r6:002862f0 r5:00000000
 r4:00000000
Rebooting in 86400 seconds..