------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 6133 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Modules linked in:
CPU: 1 UID: 0 PID: 6133 Comm: syz.4.45 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Code: a0 2d 60 8c e8 87 87 a0 fc 90 0f 0b 90 90 eb 99 e8 fb d8 df fc c6 05 d8 f8 51 0b 01 90 48 c7 c7 00 2e 60 8c e8 67 87 a0 fc 90 <0f> 0b 90 90 e9 76 ff ff ff e8 d8 d8 df fc c6 05 b2 f8 51 0b 01 90
RSP: 0018:ffffc90000a186e0 EFLAGS: 00010246
RAX: cc20c14590fb8900 RBX: ffff888032a14c24 RCX: ffff88801f320000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffffffff8155fe42 R09: 1ffff110170e519a
R10: dffffc0000000000 R11: ffffed10170e519b R12: ffff88807e342400
R13: ffff888032a14c24 R14: ffff88807e342400 R15: ffff88805f6a5218
FS:  00007f0150ac86c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c296218 CR3: 00000000640de000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 kfree_skb_reason include/linux/skbuff.h:1263 [inline]
 kfree_skb include/linux/skbuff.h:1272 [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+0x552/0xc70 net/can/j1939/transport.c:1484
 j1939_tp_cmd_recv net/can/j1939/transport.c:2089 [inline]
 j1939_tp_recv+0x8ae/0x1050 net/can/j1939/transport.c:2161
 j1939_can_recv+0x732/0xb20 net/can/j1939/main.c:108
 deliver net/can/af_can.c:573 [inline]
 can_rcv_filter+0x35b/0x7f0 net/can/af_can.c:607
 can_receive+0x327/0x480 net/can/af_can.c:664
 can_rcv+0x144/0x260 net/can/af_can.c:688
 __netif_receive_skb_one_core net/core/dev.c:5672 [inline]
 __netif_receive_skb+0x2e2/0x650 net/core/dev.c:5785
 process_backlog+0x662/0x15b0 net/core/dev.c:6117
 __napi_poll+0xcd/0x490 net/core/dev.c:6877
 napi_poll net/core/dev.c:6946 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:7068
 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 fpregs_unlock arch/x86/include/asm/fpu/api.h:80 [inline]
 copy_fpstate_to_sigframe+0x4da/0xdc0 arch/x86/kernel/fpu/signal.c:250
 get_sigframe+0x5d9/0x800 arch/x86/kernel/signal.c:163
 x64_setup_rt_frame+0x17e/0xd20 arch/x86/kernel/signal_64.c:175
 setup_rt_frame arch/x86/kernel/signal.c:250 [inline]
 handle_signal arch/x86/kernel/signal.c:294 [inline]
 arch_do_signal_or_restart+0x458/0x860 arch/x86/kernel/signal.c:339
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f014fd7e817
Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89
RSP: 002b:00007f0150ac80e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 00000000000000ca RBX: 00007f014ff36088 RCX: 00007f014fd7e819
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f014ff36088
RBP: 00007f014ff36080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f014ff3608c
R13: 0000000000000000 R14: 00007ffc622081f0 R15: 00007ffc622082d8
 </TASK>