------------[ cut here ]------------
WARNING: CPU: 1 PID: 9033 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: 9033 Comm: syz.1.1359 Not tainted 6.12.0-syzkaller #0
Hardware name: ARM-Versatile Express
Call trace: frame pointer underflow
[<8199d478>] (dump_backtrace) from [<8199d574>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:00000000 r6:82622f44 r5:00000000 r4:8203df48
[<8199d55c>] (show_stack) from [<819bba40>] (__dump_stack lib/dump_stack.c:94 [inline])
[<8199d55c>] (show_stack) from [<819bba40>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:120)
[<819bb9ec>] (dump_stack_lvl) from [<819bba80>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
 r5:00000000 r4:82870d18
[<819bba68>] (dump_stack) from [<8199e0a0>] (panic+0x120/0x374 kernel/panic.c:354)
[<8199df80>] (panic) from [<802420d8>] (check_panic_on_warn kernel/panic.c:243 [inline])
[<8199df80>] (panic) from [<802420d8>] (get_taint+0x0/0x1c kernel/panic.c:238)
 r3:8260c5c4 r2:00000001 r1:82026320 r0:8202dd88
 r7:80840e00
[<80242064>] (check_panic_on_warn) from [<8024223c>] (__warn+0x80/0x188 kernel/panic.c:748)
[<802421bc>] (__warn) from [<8024252c>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:783)
 r8:00000009 r7:8208c770 r6:df805c94 r5:84bf1800 r4:00000000
[<80242348>] (warn_slowpath_fmt) from [<80840e00>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:20000013 r9:8553ec5c r8:841cb3c0 r7:00000000 r6:8182d02c r5:00000002
 r4:841cb3c0
[<80840cc4>] (refcount_warn_saturate) from [<8149c5a8>] (__refcount_sub_and_test include/linux/refcount.h:275 [inline])
[<80840cc4>] (refcount_warn_saturate) from [<8149c5a8>] (__refcount_dec_and_test include/linux/refcount.h:307 [inline])
[<80840cc4>] (refcount_warn_saturate) from [<8149c5a8>] (refcount_dec_and_test include/linux/refcount.h:325 [inline])
[<80840cc4>] (refcount_warn_saturate) from [<8149c5a8>] (skb_unref include/linux/skbuff.h:1232 [inline])
[<80840cc4>] (refcount_warn_saturate) from [<8149c5a8>] (__sk_skb_reason_drop net/core/skbuff.c:1213 [inline])
[<80840cc4>] (refcount_warn_saturate) from [<8149c5a8>] (sk_skb_reason_drop+0x1d8/0x248 net/core/skbuff.c:1241)
[<8149c3d0>] (sk_skb_reason_drop) from [<8182d02c>] (kfree_skb_reason include/linux/skbuff.h:1262 [inline])
[<8149c3d0>] (sk_skb_reason_drop) from [<8182d02c>] (kfree_skb include/linux/skbuff.h:1271 [inline])
[<8149c3d0>] (sk_skb_reason_drop) from [<8182d02c>] (j1939_session_skb_drop_old net/can/j1939/transport.c:347 [inline])
[<8149c3d0>] (sk_skb_reason_drop) from [<8182d02c>] (j1939_xtp_rx_cts_one net/can/j1939/transport.c:1445 [inline])
[<8149c3d0>] (sk_skb_reason_drop) from [<8182d02c>] (j1939_xtp_rx_cts+0x220/0x3d0 net/can/j1939/transport.c:1484)
 r9:8553ec5c r8:841cb3c0 r7:849bc6d8 r6:00000df2 r5:8553ec00 r4:8553ec14
[<8182ce0c>] (j1939_xtp_rx_cts) from [<8182dfa0>] (j1939_tp_cmd_recv net/can/j1939/transport.c:2089 [inline])
[<8182ce0c>] (j1939_xtp_rx_cts) from [<8182dfa0>] (j1939_tp_recv+0x3f4/0x530 net/can/j1939/transport.c:2161)
 r10:ddde50c8 r9:00000040 r8:849bc6d0 r7:83b2d000 r6:83b2d008 r5:83b2d000
 r4:84934d80
[<8182dbac>] (j1939_tp_recv) from [<81827a38>] (j1939_can_recv+0x1e4/0x2dc net/can/j1939/main.c:108)
 r7:83b2d000 r6:83b2d008 r5:83b2d810 r4:84934d80
[<81827854>] (j1939_can_recv) from [<8181d808>] (deliver net/can/af_can.c:572 [inline])
[<81827854>] (j1939_can_recv) from [<8181d808>] (can_rcv_filter+0x9c/0x218 net/can/af_can.c:606)
 r9:00000040 r8:84e146a0 r7:98c80000 r6:84934a80 r5:00000001 r4:850058d0
[<8181d76c>] (can_rcv_filter) from [<8181e1ac>] (can_receive+0xb4/0xf0 net/can/af_can.c:663)
 r9:00000040 r8:00000000 r7:84e14000 r6:85102f40 r5:84d20000 r4:84934a80
[<8181e0f8>] (can_receive) from [<8181e26c>] (can_rcv+0x84/0xac net/can/af_can.c:687)
 r9:00000040 r8:00000002 r7:00000000 r6:00000000 r5:8181e1e8 r4:84934a80
[<8181e1e8>] (can_rcv) from [<814bd51c>] (__netif_receive_skb_one_core+0x5c/0x80 net/core/dev.c:5670)
 r5:8181e1e8 r4:84e14000
[<814bd4c0>] (__netif_receive_skb_one_core) from [<814bd588>] (__netif_receive_skb+0x18/0x5c net/core/dev.c:5783)
 r5:ddde51b0 r4:84934a80
[<814bd570>] (__netif_receive_skb) from [<814bd890>] (process_backlog+0xa0/0x17c net/core/dev.c:6115)
 r5:ddde51b0 r4:84934a80
[<814bd7f0>] (process_backlog) from [<814be79c>] (__napi_poll+0x34/0x240 net/core/dev.c:6779)
 r10:ddde50c0 r9:ddde5300 r8:df805ed0 r7:df805ecb r6:00000040 r5:ddde51b0
 r4:00000001
[<814be768>] (__napi_poll) from [<814bf010>] (napi_poll net/core/dev.c:6848 [inline])
[<814be768>] (__napi_poll) from [<814bf010>] (net_rx_action+0x358/0x440 net/core/dev.c:6970)
 r9:ddde5300 r8:df805ed0 r7:0000012c r6:0000dd25 r5:ddde51b0 r4:00000000
[<814becb8>] (net_rx_action) from [<8024b51c>] (handle_softirqs+0x158/0x464 kernel/softirq.c:554)
 r10:00000008 r9:84bf1800 r8:00000101 r7:00400140 r6:00000003 r5:00000004
 r4:8260408c
[<8024b3c4>] (handle_softirqs) from [<802012d0>] (__do_softirq+0x14/0x18 kernel/softirq.c:588)
 r10:003d0f00 r9:84bf18e0 r8:82870084 r7:84bf1800 r6:ecac8b10 r5:00000001
 r4:60000013
[<802012bc>] (__do_softirq) from [<80208800>] (____do_softirq+0x10/0x14 arch/arm/kernel/irq.c:77)
[<802087f0>] (____do_softirq) from [<8196c914>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40)
[<8196c8f8>] (call_with_stack) from [<8020883c>] (do_softirq_own_stack+0x38/0x3c arch/arm/kernel/irq.c:82)
[<80208804>] (do_softirq_own_stack) from [<8024ba34>] (do_softirq kernel/softirq.c:455 [inline])
[<80208804>] (do_softirq_own_stack) from [<8024ba34>] (do_softirq+0x5c/0x64 kernel/softirq.c:442)
[<8024b9d8>] (do_softirq) from [<8024bb08>] (__local_bh_enable_ip+0xcc/0xd0 kernel/softirq.c:382)
 r5:00000001 r4:84bf1800
[<8024ba3c>] (__local_bh_enable_ip) from [<80202d6c>] (local_bh_enable include/linux/bottom_half.h:33 [inline])
[<8024ba3c>] (__local_bh_enable_ip) from [<80202d6c>] (vfp_support_entry+0xac/0x2a0 arch/arm/vfp/vfpmodule.c:775)
 r5:40000000 r4:df9a1fb0
[<80202cc0>] (vfp_support_entry) from [<8020c938>] (call_undef_hook arch/arm/kernel/traps.c:449 [inline])
[<80202cc0>] (vfp_support_entry) from [<8020c938>] (do_undefinstr+0xe4/0x1e0 arch/arm/kernel/traps.c:488)
 r9:00006364 r8:80202cc0 r7:ecac8b10 r6:0014d9b0 r5:df9a1fb0 r4:8261d044
[<8020c854>] (do_undefinstr) from [<80200fe4>] (__und_usr+0x84/0xa0 arch/arm/kernel/entry-armv.S:470)
Exception stack(0xdf9a1fb0 to 0xdf9a1ff8)
1fa0:                                     76bd8b10 00000000 0fffb0d6 00db9828
1fc0: 00000000 002862f8 00189248 00189250 00000000 00006364 003d0f00 76bd80bc
1fe0: 76bd8b38 76bd7ee8 0001cad4 0014d9b0 20000010 ffffffff
 r9:00006364 r8:824b1044 r7:84bf1800 r6:ffffffff r5:20000010 r4:0014d9b4
Rebooting in 86400 seconds..