------------[ cut here ]------------
WARNING: CPU: 0 PID: 4188 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: 4188 Comm: syz.1.135 Not tainted 6.12.0-syzkaller #0
Hardware name: ARM-Versatile Express
Call trace: frame pointer underflow
[<819a4c38>] (dump_backtrace) from [<819a4d34>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:00000000 r6:82622f84 r5:00000000 r4:8203f4b0
[<819a4d1c>] (show_stack) from [<819c2e28>] (__dump_stack lib/dump_stack.c:94 [inline])
[<819a4d1c>] (show_stack) from [<819c2e28>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:120)
[<819c2dd4>] (dump_stack_lvl) from [<819c2e68>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
 r5:00000000 r4:82871d18
[<819c2e50>] (dump_stack) from [<819a5860>] (panic+0x120/0x374 kernel/panic.c:354)
[<819a5740>] (panic) from [<802420d8>] (check_panic_on_warn kernel/panic.c:243 [inline])
[<819a5740>] (panic) from [<802420d8>] (get_taint+0x0/0x1c kernel/panic.c:238)
 r3:8260c604 r2:00000001 r1:82027874 r0:8202f328
 r7:808452e0
[<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 r7:8208e130 r6:df801c74 r5:83496c00 r4:00000000
[<80242348>] (warn_slowpath_fmt) from [<808452e0>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:dddd10c8 r9:00000040 r8:837bc490 r7:00000000 r6:81832234 r5:00000002
 r4:844e9300
[<808451a4>] (refcount_warn_saturate) from [<814a3ce0>] (__refcount_sub_and_test include/linux/refcount.h:275 [inline])
[<808451a4>] (refcount_warn_saturate) from [<814a3ce0>] (__refcount_dec_and_test include/linux/refcount.h:307 [inline])
[<808451a4>] (refcount_warn_saturate) from [<814a3ce0>] (refcount_dec_and_test include/linux/refcount.h:325 [inline])
[<808451a4>] (refcount_warn_saturate) from [<814a3ce0>] (skb_unref include/linux/skbuff.h:1232 [inline])
[<808451a4>] (refcount_warn_saturate) from [<814a3ce0>] (__sk_skb_reason_drop net/core/skbuff.c:1213 [inline])
[<808451a4>] (refcount_warn_saturate) from [<814a3ce0>] (sk_skb_reason_drop+0x1d8/0x248 net/core/skbuff.c:1241)
[<814a3b08>] (sk_skb_reason_drop) from [<81832234>] (kfree_skb_reason include/linux/skbuff.h:1262 [inline])
[<814a3b08>] (sk_skb_reason_drop) from [<81832234>] (kfree_skb include/linux/skbuff.h:1271 [inline])
[<814a3b08>] (sk_skb_reason_drop) from [<81832234>] (j1939_session_destroy+0x78/0x200 net/can/j1939/transport.c:282)
 r9:00000040 r8:837bc490 r7:8491d81c r6:85002450 r5:85002400 r4:844e9300
[<818321bc>] (j1939_session_destroy) from [<81833394>] (__j1939_session_release net/can/j1939/transport.c:294 [inline])
[<818321bc>] (j1939_session_destroy) from [<81833394>] (kref_put include/linux/kref.h:65 [inline])
[<818321bc>] (j1939_session_destroy) from [<81833394>] (j1939_session_put net/can/j1939/transport.c:299 [inline])
[<818321bc>] (j1939_session_destroy) from [<81833394>] (j1939_xtp_rx_eoma+0x120/0x234 net/can/j1939/transport.c:1411)
 r6:844e90c0 r5:85002400 r4:85002414
[<81833274>] (j1939_xtp_rx_eoma) from [<818357bc>] (j1939_tp_cmd_recv net/can/j1939/transport.c:2113 [inline])
[<81833274>] (j1939_xtp_rx_eoma) from [<818357bc>] (j1939_tp_recv+0x4a8/0x530 net/can/j1939/transport.c:2161)
 r7:8491d000 r6:8491d008 r5:8491d000 r4:844e90c0
[<81835314>] (j1939_tp_recv) from [<8182f1a0>] (j1939_can_recv+0x1e4/0x2dc net/can/j1939/main.c:108)
 r7:8491d000 r6:8491d008 r5:8491d810 r4:844e90c0
[<8182efbc>] (j1939_can_recv) from [<81824f70>] (deliver net/can/af_can.c:572 [inline])
[<8182efbc>] (j1939_can_recv) from [<81824f70>] (can_rcv_filter+0x9c/0x218 net/can/af_can.c:606)
 r9:00000040 r8:844c0680 r7:98ec0000 r6:844e9f00 r5:00000001 r4:847a83c0
[<81824ed4>] (can_rcv_filter) from [<81825914>] (can_receive+0xb4/0xf0 net/can/af_can.c:663)
 r9:00000040 r8:00000000 r7:844c0000 r6:84331fc0 r5:843b8000 r4:844e9f00
[<81825860>] (can_receive) from [<818259d4>] (can_rcv+0x84/0xac net/can/af_can.c:687)
 r9:00000040 r8:00000001 r7:00000000 r6:00000000 r5:81825950 r4:844e9f00
[<81825950>] (can_rcv) from [<814c4c54>] (__netif_receive_skb_one_core+0x5c/0x80 net/core/dev.c:5670)
 r5:81825950 r4:844c0000
[<814c4bf8>] (__netif_receive_skb_one_core) from [<814c4cc0>] (__netif_receive_skb+0x18/0x5c net/core/dev.c:5783)
 r5:dddd11b0 r4:844e9f00
[<814c4ca8>] (__netif_receive_skb) from [<814c4fc8>] (process_backlog+0xa0/0x17c net/core/dev.c:6115)
 r5:dddd11b0 r4:844e9f00
[<814c4f28>] (process_backlog) from [<814c5ed4>] (__napi_poll+0x34/0x240 net/core/dev.c:6779)
 r10:dddd10c0 r9:dddd1300 r8:df801ed0 r7:df801ecb r6:00000040 r5:dddd11b0
 r4:00000001
[<814c5ea0>] (__napi_poll) from [<814c6748>] (napi_poll net/core/dev.c:6848 [inline])
[<814c5ea0>] (__napi_poll) from [<814c6748>] (net_rx_action+0x358/0x440 net/core/dev.c:6970)
 r9:dddd1300 r8:df801ed0 r7:0000012c r6:ffffc819 r5:dddd11b0 r4:00000000
[<814c63f0>] (net_rx_action) from [<8024b508>] (handle_softirqs+0x158/0x464 kernel/softirq.c:554)
 r10:00000008 r9:83496c00 r8:00000101 r7:00400040 r6:00000003 r5:00000004
 r4:8260408c
[<8024b3b0>] (handle_softirqs) from [<802012d0>] (__do_softirq+0x14/0x18 kernel/softirq.c:588)
 r10:00000000 r9:83496ce0 r8:82871084 r7:83496c00 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 [<819740c4>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40)
[<819740a8>] (call_with_stack) from [<8020883c>] (do_softirq_own_stack+0x38/0x3c arch/arm/kernel/irq.c:82)
[<80208804>] (do_softirq_own_stack) from [<8024ba20>] (do_softirq kernel/softirq.c:455 [inline])
[<80208804>] (do_softirq_own_stack) from [<8024ba20>] (do_softirq+0x5c/0x64 kernel/softirq.c:442)
[<8024b9c4>] (do_softirq) from [<8024baf4>] (__local_bh_enable_ip+0xcc/0xd0 kernel/softirq.c:382)
 r5:00000001 r4:83496c00
[<8024ba28>] (__local_bh_enable_ip) from [<80202d6c>] (local_bh_enable include/linux/bottom_half.h:33 [inline])
[<8024ba28>] (__local_bh_enable_ip) from [<80202d6c>] (vfp_support_entry+0xac/0x2a0 arch/arm/vfp/vfpmodule.c:775)
 r5:40000000 r4:dff5dfb0
[<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)
 r9:002862c4 r8:80202cc0 r7:ecac8b10 r6:0014d9b0 r5:dff5dfb0 r4:8261d084
[<8020c854>] (do_undefinstr) from [<80200fe4>] (__und_usr+0x84/0xa0 arch/arm/kernel/entry-armv.S:470)
Exception stack(0xdff5dfb0 to 0xdff5dff8)
dfa0:                                     015da550 00000000 0fffb0d6 00db9828
dfc0: 00000000 00000000 002862b8 00000000 00000000 002862c4 00000000 fffffffe
dfe0: 015da578 7e836838 00024ff4 0014d9b0 20000010 ffffffff
 r9:002862c4 r8:824b1044 r7:83496c00 r6:ffffffff r5:20000010 r4:0014d9b4
Rebooting in 86400 seconds..