------------[ cut here ]------------
WARNING: CPU: 1 PID: 5663 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: 5663 Comm: syz.1.580 Not tainted 6.12.0-rc7-syzkaller #0
Hardware name: ARM-Versatile Express
Call trace: frame pointer underflow
[<8199d4f8>] (dump_backtrace) from [<8199d5f4>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:00000000 r6:82622f44 r5:00000000 r4:8203df84
[<8199d5dc>] (show_stack) from [<819bbac0>] (__dump_stack lib/dump_stack.c:94 [inline])
[<8199d5dc>] (show_stack) from [<819bbac0>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:120)
[<819bba6c>] (dump_stack_lvl) from [<819bbb00>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
 r5:00000000 r4:82870d18
[<819bbae8>] (dump_stack) from [<8199e120>] (panic+0x120/0x374 kernel/panic.c:354)
[<8199e000>] (panic) from [<80242118>] (check_panic_on_warn kernel/panic.c:243 [inline])
[<8199e000>] (panic) from [<80242118>] (get_taint+0x0/0x1c kernel/panic.c:238)
 r3:8260c5c4 r2:00000001 r1:82026358 r0:8202ddc0
 r7:80840e78
[<802420a4>] (check_panic_on_warn) from [<8024227c>] (__warn+0x80/0x188 kernel/panic.c:748)
[<802421fc>] (__warn) from [<8024256c>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:783)
 r8:00000009 r7:8208c7ac r6:df805c74 r5:84572400 r4:00000000
[<80242388>] (warn_slowpath_fmt) from [<80840e78>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:ddde50c8 r9:84b84cc0 r8:8425381c r7:00000000 r6:8182ab44 r5:00000002
 r4:84b84a80
[<80840d3c>] (refcount_warn_saturate) from [<8149c620>] (__refcount_sub_and_test include/linux/refcount.h:275 [inline])
[<80840d3c>] (refcount_warn_saturate) from [<8149c620>] (__refcount_dec_and_test include/linux/refcount.h:307 [inline])
[<80840d3c>] (refcount_warn_saturate) from [<8149c620>] (refcount_dec_and_test include/linux/refcount.h:325 [inline])
[<80840d3c>] (refcount_warn_saturate) from [<8149c620>] (skb_unref include/linux/skbuff.h:1232 [inline])
[<80840d3c>] (refcount_warn_saturate) from [<8149c620>] (__sk_skb_reason_drop net/core/skbuff.c:1213 [inline])
[<80840d3c>] (refcount_warn_saturate) from [<8149c620>] (sk_skb_reason_drop+0x1d8/0x248 net/core/skbuff.c:1241)
[<8149c448>] (sk_skb_reason_drop) from [<8182ab44>] (kfree_skb_reason include/linux/skbuff.h:1262 [inline])
[<8149c448>] (sk_skb_reason_drop) from [<8182ab44>] (kfree_skb include/linux/skbuff.h:1271 [inline])
[<8149c448>] (sk_skb_reason_drop) from [<8182ab44>] (j1939_session_destroy+0x78/0x200 net/can/j1939/transport.c:282)
 r9:84b84cc0 r8:8425381c r7:84253814 r6:847d3050 r5:847d3000 r4:84b84a80
[<8182aacc>] (j1939_session_destroy) from [<8182e330>] (__j1939_session_release net/can/j1939/transport.c:294 [inline])
[<8182aacc>] (j1939_session_destroy) from [<8182e330>] (kref_put include/linux/kref.h:65 [inline])
[<8182aacc>] (j1939_session_destroy) from [<8182e330>] (j1939_session_put net/can/j1939/transport.c:299 [inline])
[<8182aacc>] (j1939_session_destroy) from [<8182e330>] (j1939_simple_recv+0x1dc/0x1e4 net/can/j1939/transport.c:2192)
 r6:84253000 r5:847d3000 r4:847d3014
[<8182e154>] (j1939_simple_recv) from [<81827b04>] (j1939_can_recv+0x238/0x2dc net/can/j1939/main.c:112)
 r9:00000040 r8:85073b10 r7:84253000 r6:84253008 r5:84253810 r4:84b84cc0
[<818278cc>] (j1939_can_recv) from [<8181d880>] (deliver net/can/af_can.c:572 [inline])
[<818278cc>] (j1939_can_recv) from [<8181d880>] (can_rcv_filter+0x9c/0x218 net/can/af_can.c:606)
 r9:00000040 r8:844b0680 r7:9800fd00 r6:84b84b40 r5:00000001 r4:8426b360
[<8181d7e4>] (can_rcv_filter) from [<8181e224>] (can_receive+0xb4/0xf0 net/can/af_can.c:663)
 r9:00000040 r8:00000000 r7:844b0000 r6:8447bd00 r5:84440000 r4:84b84b40
[<8181e170>] (can_receive) from [<8181e2e4>] (can_rcv+0x84/0xac net/can/af_can.c:687)
 r9:00000040 r8:00000001 r7:00000000 r6:00000000 r5:8181e260 r4:84b84b40
[<8181e260>] (can_rcv) from [<814bd594>] (__netif_receive_skb_one_core+0x5c/0x80 net/core/dev.c:5670)
 r5:8181e260 r4:844b0000
[<814bd538>] (__netif_receive_skb_one_core) from [<814bd600>] (__netif_receive_skb+0x18/0x5c net/core/dev.c:5783)
 r5:ddde51b0 r4:84b84b40
[<814bd5e8>] (__netif_receive_skb) from [<814bd908>] (process_backlog+0xa0/0x17c net/core/dev.c:6115)
 r5:ddde51b0 r4:84b84b40
[<814bd868>] (process_backlog) from [<814be814>] (__napi_poll+0x34/0x240 net/core/dev.c:6779)
 r10:ddde50c0 r9:ddde5300 r8:df805ea0 r7:df805e9b r6:00000040 r5:ddde51b0
 r4:00000001
[<814be7e0>] (__napi_poll) from [<814bf088>] (napi_poll net/core/dev.c:6848 [inline])
[<814be7e0>] (__napi_poll) from [<814bf088>] (net_rx_action+0x358/0x440 net/core/dev.c:6970)
 r9:ddde5300 r8:df805ea0 r7:0000012c r6:000083f1 r5:ddde51b0 r4:00000000
[<814bed30>] (net_rx_action) from [<8024b55c>] (handle_softirqs+0x158/0x464 kernel/softirq.c:554)
 r10:00000008 r9:84572400 r8:00000100 r7:00400040 r6:00000003 r5:00000004
 r4:8260408c
[<8024b404>] (handle_softirqs) from [<8024b958>] (__do_softirq kernel/softirq.c:588 [inline])
[<8024b404>] (handle_softirqs) from [<8024b958>] (invoke_softirq kernel/softirq.c:428 [inline])
[<8024b404>] (handle_softirqs) from [<8024b958>] (__irq_exit_rcu+0xa4/0x164 kernel/softirq.c:637)
 r10:00000000 r9:84572400 r8:00000000 r7:dff49cd8 r6:821dfb68 r5:82220374
 r4:84572400
[<8024b8b4>] (__irq_exit_rcu) from [<8024bc58>] (irq_exit+0x10/0x18 kernel/softirq.c:661)
 r5:82220374 r4:824bbcdc
[<8024bc48>] (irq_exit) from [<819bc49c>] (generic_handle_arch_irq+0x7c/0x80 kernel/irq/handle.c:240)
[<819bc420>] (generic_handle_arch_irq) from [<8196c98c>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40)
 r9:84572400 r8:00000000 r7:dff49d0c r6:ffffffff r5:20000013 r4:8182be40
[<8196c970>] (call_with_stack) from [<80200bcc>] (__irq_svc+0x8c/0xbc arch/arm/kernel/entry-armv.S:227)
Exception stack(0xdff49cd8 to 0xdff49d20)
9cc0:                                                       847d3000 00000003
9ce0: 00000004 847d3014 00000002 8330b400 847d3000 dff49f38 00000000 858cea84
9d00: 00000000 dff49d34 00000000 dff49d28 81829e90 8182be40 20000013 ffffffff
[<8182be0c>] (j1939_session_put) from [<81829e90>] (j1939_sk_send_loop net/can/j1939/socket.c:1202 [inline])
[<8182be0c>] (j1939_session_put) from [<81829e90>] (j1939_sk_sendmsg+0x41c/0x548 net/can/j1939/socket.c:1277)
[<81829a74>] (j1939_sk_sendmsg) from [<8148727c>] (sock_sendmsg_nosec net/socket.c:729 [inline])
[<81829a74>] (j1939_sk_sendmsg) from [<8148727c>] (__sock_sendmsg+0x44/0x78 net/socket.c:744)
 r10:00000000 r9:dff49dd4 r8:dff49dd4 r7:8330b400 r6:8330b400 r5:dff49f38
 r4:00000000
[<81487238>] (__sock_sendmsg) from [<8148827c>] (____sys_sendmsg+0x2a4/0x2c4 net/socket.c:2607)
 r7:8330b400 r6:00000000 r5:00000001 r4:dff49f38
[<81487fd8>] (____sys_sendmsg) from [<8148a1e4>] (___sys_sendmsg+0x9c/0xd0 net/socket.c:2661)
 r10:dff49e34 r9:20001200 r8:00000001 r7:00000000 r6:8330b400 r5:dff49f38
 r4:00000000
[<8148a148>] (___sys_sendmsg) from [<8148a6fc>] (__sys_sendmsg net/socket.c:2690 [inline])
[<8148a148>] (___sys_sendmsg) from [<8148a6fc>] (__do_sys_sendmsg net/socket.c:2699 [inline])
[<8148a148>] (___sys_sendmsg) from [<8148a6fc>] (sys_sendmsg+0x78/0xbc net/socket.c:2697)
 r10:00000128 r9:84572400 r8:8020029c r7:00000001 r6:20001200 r5:8330b400
 r4:00000000
[<8148a684>] (sys_sendmsg) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67)
Exception stack(0xdff49fa8 to 0xdff49ff0)
9fa0:                   00000000 00000000 00000003 20001200 00000001 00000000
9fc0: 00000000 00000000 002862f0 00000128 00000000 00006364 003d0f00 76b8c0bc
9fe0: 76b8bec0 76b8beb0 00018af0 00133450
 r7:00000128 r6:002862f0 r5:00000000 r4:00000000
Rebooting in 86400 seconds..