vxcan0: j1939_xtp_rx_abort_one: 0xffff888000427800: 0x20000: (3) A timeout occurred and this is the connection abort to close the session. ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 3 PID: 34 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 3 UID: 0 PID: 34 Comm: ksoftirqd/3 Not tainted 6.12.0-rc1-syzkaller-00306-g27cc6fdf7201 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Code: ff 89 de e8 a8 2e 04 fd 84 db 0f 85 66 ff ff ff e8 bb 2c 04 fd c6 05 0a 14 7d 0b 01 90 48 c7 c7 60 d6 b0 8b e8 07 ac c5 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 98 2c 04 fd 0f b6 1d e5 13 7d 0b 31 RSP: 0018:ffffc900005c77c8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff814e28b9 RDX: ffff88801bb7c880 RSI: ffffffff814e28c6 RDI: 0000000000000001 RBP: ffff88802ac160e4 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffff88802ac160e4 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88802b700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020028000 CR3: 0000000026246000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:275 [inline] __refcount_dec_and_test include/linux/refcount.h:307 [inline] refcount_dec_and_test include/linux/refcount.h:325 [inline] skb_unref include/linux/skbuff.h:1232 [inline] __sk_skb_reason_drop net/core/skbuff.c:1213 [inline] sk_skb_reason_drop+0x183/0x1a0 net/core/skbuff.c:1241 kfree_skb_reason include/linux/skbuff.h:1262 [inline] kfree_skb include/linux/skbuff.h:1271 [inline] j1939_session_destroy+0x163/0x460 net/can/j1939/transport.c:282 __j1939_session_release net/can/j1939/transport.c:294 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put net/can/j1939/transport.c:299 [inline] j1939_xtp_rx_abort_one+0x3f9/0x560 net/can/j1939/transport.c:1354 j1939_xtp_rx_abort net/can/j1939/transport.c:1362 [inline] j1939_tp_cmd_recv net/can/j1939/transport.c:2128 [inline] j1939_tp_recv+0xcf8/0xf50 net/can/j1939/transport.c:2161 j1939_can_recv net/can/j1939/main.c:108 [inline] j1939_can_recv+0x78f/0xa50 net/can/j1939/main.c:34 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x2a8/0x900 net/can/af_can.c:606 can_receive+0x320/0x5c0 net/can/af_can.c:663 can_rcv+0x1e2/0x280 net/can/af_can.c:687 __netif_receive_skb_one_core+0x1b1/0x1e0 net/core/dev.c:5666 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5779 process_backlog+0x443/0x15f0 net/core/dev.c:6111 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6966 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 run_ksoftirqd kernel/softirq.c:927 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:919 smpboot_thread_fn+0x661/0xa30 kernel/smpboot.c:164 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244