------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 8554 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 8554 Comm: syz.6.701 Not tainted 6.13.0-rc1-syzkaller-00036-g5076001689e4 #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: e0 1e 5f 8c e8 87 c5 95 fc 90 0f 0b 90 90 eb 99 e8 2b 1e d5 fc c6 05 2d 2c 39 0b 01 90 48 c7 c7 40 1f 5f 8c e8 67 c5 95 fc 90 <0f> 0b 90 90 e9 76 ff ff ff e8 08 1e d5 fc c6 05 07 2c 39 0b 01 90
RSP: 0018:ffffc90000007768 EFLAGS: 00010246
RAX: 073c02f51bd7cf00 RBX: ffff88804838a864 RCX: ffff88801cf93c00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffffffff81601c02 R09: fffffbfff1cfa210
R10: dffffc0000000000 R11: fffffbfff1cfa210 R12: ffff888032799068
R13: ffff88804838a864 R14: 1ffff110064f3218 R15: ffff888032799000
FS:  00007f4a8d2c36c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3011a7 CR3: 00000000589a2000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 kfree_skb_reason include/linux/skbuff.h:1263 [inline]
 kfree_skb include/linux/skbuff.h:1272 [inline]
 j1939_session_destroy net/can/j1939/transport.c:282 [inline]
 __j1939_session_release net/can/j1939/transport.c:294 [inline]
 kref_put include/linux/kref.h:65 [inline]
 j1939_session_put+0x1ed/0x440 net/can/j1939/transport.c:299
 j1939_can_recv+0x758/0xb20 net/can/j1939/main.c:112
 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+0x2d6/0x9b0 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 j1939_sk_sendmsg+0x1293/0x14c0 net/can/j1939/socket.c:1280
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:726
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583
 ___sys_sendmsg net/socket.c:2637 [inline]
 __sys_sendmsg+0x269/0x350 net/socket.c:2669
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4a8c57ff19
Code: 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 01 48
RSP: 002b:00007f4a8d2c3058 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4a8c745fa0 RCX: 00007f4a8c57ff19
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007f4a8c5f3986 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4a8c745fa0 R15: 00007ffd2850ba58
 </TASK>