------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 24 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
Modules linked in:
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.12.0-rc1-syzkaller-g80cb3fb61135 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
lr : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
sp : ffff800097987490
x29: ffff800097987490 x28: dfff800000000000 x27: ffff0000d5a020e4
x26: ffff0000d5a02000 x25: 00000000000006f9 x24: 0000000000000000
x23: ffff0000d5a020e4 x22: ffff80008a586bd8 x21: 0000000000000003
x20: ffff0000d5a020e4 x19: ffff800092a80000 x18: 0000000000000008
x17: 0000000000000000 x16: ffff8000830b4c50 x15: 0000000000000001
x14: 1fffe000366cc0e2 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000102 x10: 0000000000ff0100 x9 : a39bf47e12e4a600
x8 : a39bf47e12e4a600 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800097986bb8 x4 : ffff80008f8dcac0 x3 : ffff800080626e34
x2 : 0000000000000001 x1 : 0000000100000100 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
 __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+0x210/0x43c net/core/skbuff.c:1241
 kfree_skb_reason include/linux/skbuff.h:1262 [inline]
 kfree_skb include/linux/skbuff.h:1271 [inline]
 j1939_session_skb_drop_old net/can/j1939/transport.c:347 [inline]
 j1939_xtp_rx_cts_one net/can/j1939/transport.c:1445 [inline]
 j1939_xtp_rx_cts+0x464/0xafc net/can/j1939/transport.c:1484
 j1939_tp_cmd_recv net/can/j1939/transport.c:2089 [inline]
 j1939_tp_recv+0x730/0xe14 net/can/j1939/transport.c:2161
 j1939_can_recv+0x5bc/0x934 net/can/j1939/main.c:108
 deliver net/can/af_can.c:572 [inline]
 can_rcv_filter+0x308/0x714 net/can/af_can.c:606
 can_receive+0x328/0x488 net/can/af_can.c:663
 can_rcv+0x128/0x240 net/can/af_can.c:687
 __netif_receive_skb_one_core net/core/dev.c:5662 [inline]
 __netif_receive_skb+0x18c/0x3c8 net/core/dev.c:5775
 process_backlog+0x640/0x123c net/core/dev.c:6107
 __napi_poll+0xb4/0x3fc net/core/dev.c:6771
 napi_poll net/core/dev.c:6840 [inline]
 net_rx_action+0x6a8/0xf4c net/core/dev.c:6962
 handle_softirqs+0x2e0/0xbf8 kernel/softirq.c:554
 run_ksoftirqd+0x70/0x158 kernel/softirq.c:927
 smpboot_thread_fn+0x4b0/0x90c kernel/smpboot.c:164
 kthread+0x288/0x310 kernel/kthread.c:389
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
irq event stamp: 1060821
hardirqs last  enabled at (1060820): [<ffff80008039c81c>] __up_console_sem kernel/printk/printk.c:344 [inline]
hardirqs last  enabled at (1060820): [<ffff80008039c81c>] __console_unlock+0x70/0xc4 kernel/printk/printk.c:2844
hardirqs last disabled at (1060821): [<ffff80008b481ff4>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:479
softirqs last  enabled at (1060742): [<ffff800080206648>] softirq_handle_end kernel/softirq.c:400 [inline]
softirqs last  enabled at (1060742): [<ffff800080206648>] handle_softirqs+0xa38/0xbf8 kernel/softirq.c:582
softirqs last disabled at (1060745): [<ffff8000802095b8>] run_ksoftirqd+0x70/0x158 kernel/softirq.c:927
---[ end trace 0000000000000000 ]---
vkms_vblank_simulate: vblank timer overrun