vxcan1: j1939_tp_rxtimer: 0x851a4b00: rx timeout, send abort vxcan1: j1939_xtp_rx_abort_one: 0x851a4b00: 0x0ff00: (3) A timeout occurred and this is the connection abort to close the session. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 23 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: 23 Comm: ksoftirqd/1 Not tainted 6.11.0-syzkaller #0 Hardware name: ARM-Versatile Express Call trace: [<81966cb8>] (dump_backtrace) from [<81966db4>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:00000000 r6:826228c4 r5:00000000 r4:8200e404 [<81966d9c>] (show_stack) from [<81984a58>] (__dump_stack lib/dump_stack.c:93 [inline]) [<81966d9c>] (show_stack) from [<81984a58>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:119) [<81984a04>] (dump_stack_lvl) from [<81984a98>] (dump_stack+0x18/0x1c lib/dump_stack.c:128) r5:00000000 r4:8286ed18 [<81984a80>] (dump_stack) from [<8196785c>] (panic+0x120/0x368 kernel/panic.c:354) [<8196773c>] (panic) from [<802421d4>] (check_panic_on_warn kernel/panic.c:243 [inline]) [<8196773c>] (panic) from [<802421d4>] (get_taint+0x0/0x1c kernel/panic.c:238) r3:8260c5c4 r2:00000001 r1:81ff6c38 r0:81ffea04 r7:8081a110 [<80242160>] (check_panic_on_warn) from [<80242328>] (__warn+0x7c/0x180 kernel/panic.c:741) [<802422ac>] (__warn) from [<80242614>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:774) r8:00000009 r7:8205cdc4 r6:df879bd4 r5:82e42400 r4:00000000 [<80242430>] (warn_slowpath_fmt) from [<8081a110>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28) r10:ddde4ec8 r9:00000003 r8:00000001 r7:00000000 r6:817f4e34 r5:00000002 r4:85432180 [<80819fd4>] (refcount_warn_saturate) from [<8146782c>] (__refcount_sub_and_test include/linux/refcount.h:275 [inline]) [<80819fd4>] (refcount_warn_saturate) from [<8146782c>] (__refcount_dec_and_test include/linux/refcount.h:307 [inline]) [<80819fd4>] (refcount_warn_saturate) from [<8146782c>] (refcount_dec_and_test include/linux/refcount.h:325 [inline]) [<80819fd4>] (refcount_warn_saturate) from [<8146782c>] (skb_unref include/linux/skbuff.h:1232 [inline]) [<80819fd4>] (refcount_warn_saturate) from [<8146782c>] (__sk_skb_reason_drop net/core/skbuff.c:1213 [inline]) [<80819fd4>] (refcount_warn_saturate) from [<8146782c>] (sk_skb_reason_drop+0x1d8/0x248 net/core/skbuff.c:1241) [<81467654>] (sk_skb_reason_drop) from [<817f4e34>] (kfree_skb_reason include/linux/skbuff.h:1262 [inline]) [<81467654>] (sk_skb_reason_drop) from [<817f4e34>] (kfree_skb include/linux/skbuff.h:1271 [inline]) [<81467654>] (sk_skb_reason_drop) from [<817f4e34>] (j1939_session_destroy+0x78/0x200 net/can/j1939/transport.c:282) r9:00000003 r8:00000001 r7:84e6b81c r6:851a4b50 r5:851a4b00 r4:85432180 [<817f4dbc>] (j1939_session_destroy) from [<817f5620>] (__j1939_session_release net/can/j1939/transport.c:294 [inline]) [<817f4dbc>] (j1939_session_destroy) from [<817f5620>] (kref_put include/linux/kref.h:65 [inline]) [<817f4dbc>] (j1939_session_destroy) from [<817f5620>] (j1939_session_put net/can/j1939/transport.c:299 [inline]) [<817f4dbc>] (j1939_session_destroy) from [<817f5620>] (j1939_xtp_rx_abort_one+0xbc/0x2a4 net/can/j1939/transport.c:1354) r6:84e6b000 r5:851a4b00 r4:85432780 [<817f5564>] (j1939_xtp_rx_abort_one) from [<817f83d8>] (j1939_xtp_rx_abort net/can/j1939/transport.c:1362 [inline]) [<817f5564>] (j1939_xtp_rx_abort_one) from [<817f83d8>] (j1939_tp_cmd_recv net/can/j1939/transport.c:2128 [inline]) [<817f5564>] (j1939_xtp_rx_abort_one) from [<817f83d8>] (j1939_tp_recv+0x4c4/0x530 net/can/j1939/transport.c:2161) r9:00000040 r8:84795d50 r7:84e6b000 r6:84e6b008 r5:84e6b000 r4:85432780 [<817f7f14>] (j1939_tp_recv) from [<817f1da0>] (j1939_can_recv+0x1e4/0x2dc net/can/j1939/main.c:108) r7:84e6b000 r6:84e6b008 r5:84e6b810 r4:85432780 [<817f1bbc>] (j1939_can_recv) from [<817e7b6c>] (deliver net/can/af_can.c:572 [inline]) [<817f1bbc>] (j1939_can_recv) from [<817e7b6c>] (can_rcv_filter+0x9c/0x218 net/can/af_can.c:606) r9:00000040 r8:847c46a0 r7:98ec0000 r6:854329c0 r5:00000001 r4:84f2e7e0 [<817e7ad0>] (can_rcv_filter) from [<817e8510>] (can_receive+0xb4/0xf0 net/can/af_can.c:663) r9:00000040 r8:00000000 r7:847c4000 r6:85396200 r5:84696800 r4:854329c0 [<817e845c>] (can_receive) from [<817e85d0>] (can_rcv+0x84/0xac net/can/af_can.c:687) r9:00000040 r8:00000002 r7:00000000 r6:00000000 r5:817e854c r4:854329c0 [<817e854c>] (can_rcv) from [<814886a4>] (__netif_receive_skb_one_core+0x5c/0x80 net/core/dev.c:5662) r5:817e854c r4:847c4000 [<81488648>] (__netif_receive_skb_one_core) from [<81488710>] (__netif_receive_skb+0x18/0x5c net/core/dev.c:5775) r5:ddde4fb0 r4:854329c0 [<814886f8>] (__netif_receive_skb) from [<81488a00>] (process_backlog+0x88/0x15c net/core/dev.c:6107) r5:ddde4fb0 r4:854329c0 [<81488978>] (process_backlog) from [<81489904>] (__napi_poll+0x34/0x240 net/core/dev.c:6771) r10:ddde4ec0 r9:ddde5100 r8:df879e38 r7:df879e33 r6:00000040 r5:ddde4fb0 r4:00000001 [<814898d0>] (__napi_poll) from [<8148a13c>] (napi_poll net/core/dev.c:6840 [inline]) [<814898d0>] (__napi_poll) from [<8148a13c>] (net_rx_action+0x338/0x420 net/core/dev.c:6962) r9:ddde5100 r8:df879e38 r7:0000012c r6:00021ff1 r5:ddde4fb0 r4:00000000 [<81489e04>] (net_rx_action) from [<8024b5d8>] (handle_softirqs+0x15c/0x468 kernel/softirq.c:554) r10:00000002 r9:82e42400 r8:00000100 r7:04208040 r6:00000003 r5:00000002 r4:8260408c [<8024b47c>] (handle_softirqs) from [<8024b928>] (run_ksoftirqd kernel/softirq.c:928 [inline]) [<8024b47c>] (handle_softirqs) from [<8024b928>] (run_ksoftirqd+0x44/0x4c kernel/softirq.c:920) r10:00000000 r9:00000002 r8:826240c8 r7:00000001 r6:82cc7440 r5:82e42400 r4:00000001 [<8024b8e4>] (run_ksoftirqd) from [<80274f1c>] (smpboot_thread_fn+0x16c/0x288 kernel/smpboot.c:164) [<80274db0>] (smpboot_thread_fn) from [<8026faf4>] (kthread+0x104/0x134 kernel/kthread.c:389) r10:00000000 r9:df819d60 r8:82cc76c0 r7:82cc7440 r6:80274db0 r5:82e42400 r4:82cc75c0 r3:00000000 [<8026f9f0>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xdf879fb0 to 0xdf879ff8) 9fa0: 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:8026f9f0 r4:82cc75c0 Rebooting in 86400 seconds..