------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 7417 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 7417 Comm: syz.0.152 Not tainted 6.12.0-rc1-syzkaller-g3eddb108abe3 #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 : ffff80009cdf76e0
x29: ffff80009cdf76e0 x28: 0000000000000001 x27: 00000000ffffffff
x26: 1fffe0001de2a898 x25: dfff800000000000 x24: 0000000000000000
x23: ffff0000d761dae4 x22: ffff80008a57d30c x21: 0000000000000003
x20: ffff0000d761dae4 x19: ffff800092a70000 x18: 1fffe000366c7c76
x17: ffff80008f7dd000 x16: ffff800080355404 x15: 0000000000000001
x14: 1fffe000366ca720 x13: 0000000000000000 x12: 0000000000000003
x11: 0000000000000001 x10: 0000000000000003 x9 : aadfc1b05f9bec00
x8 : aadfc1b05f9bec00 x7 : ffff8000802c3cec x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000006 x1 : ffff80008b5f4f00 x0 : ffff800123f0f000
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_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+0x1c8/0x460 net/can/j1939/transport.c:299
 j1939_sk_send_loop net/can/j1939/socket.c:1202 [inline]
 j1939_sk_sendmsg+0xe88/0x10d0 net/can/j1939/socket.c:1277
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg net/socket.c:744 [inline]
 ____sys_sendmsg+0x56c/0x840 net/socket.c:2602
 ___sys_sendmsg net/socket.c:2656 [inline]
 __sys_sendmsg+0x26c/0x33c net/socket.c:2685
 __do_sys_sendmsg net/socket.c:2694 [inline]
 __se_sys_sendmsg net/socket.c:2692 [inline]
 __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2692
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
irq event stamp: 612
hardirqs last  enabled at (611): [<ffff8000802c3d8c>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1517 [inline]
hardirqs last  enabled at (611): [<ffff8000802c3d8c>] finish_lock_switch+0xbc/0x1e4 kernel/sched/core.c:5069
hardirqs last disabled at (612): [<ffff80008b481418>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:470
softirqs last  enabled at (594): [<ffff800080203e40>] softirq_handle_end kernel/softirq.c:400 [inline]
softirqs last  enabled at (594): [<ffff800080203e40>] handle_softirqs+0xa38/0xbf8 kernel/softirq.c:582
softirqs last disabled at (553): [<ffff800080020db4>] __do_softirq+0x14/0x20 kernel/softirq.c:588
---[ end trace 0000000000000000 ]---