------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 6364 at lib/refcount.c:25 refcount_warn_saturate+0x108/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 6364 Comm: syz-executor.1 Not tainted 5.12.0-syzkaller-08136-gd72cd4ad4174 #0
Hardware name: linux,dummy-virt (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--)
pc : refcount_warn_saturate+0x108/0x1a0 lib/refcount.c:25
lr : refcount_warn_saturate+0x108/0x1a0 lib/refcount.c:25
sp : ffff800019027b30
x29: ffff800019027b30 x28: ffff80001717cd00 
x27: ffff0000108b8000 x26: ffff00002f2a0568 
x25: 1fffe00005e540ad x24: 1fffe00005e8080a 
x23: ffff0000108b8000 x22: ffff800014fe3160 
x21: ffff00002f050000 x20: ffff0000108b9108 
x19: 0000000000000002 x18: ffff00006ab3bb48 
x17: 0000000000000000 x16: 0000000000000000 
x15: ffff00006ab3bb7c x14: 1ffff00003204ea4 
x13: 0000000000000001 x12: ffff60000d569697 
x11: 1fffe0000d569696 x10: ffff60000d569696 
x9 : dfff800000000000 x8 : ffff00006ab4b4b7 
x7 : 0000000000000001 x6 : 00009ffff2a9696a 
x5 : ffff00006ab4b4b0 x4 : 1fffe00005e0a001 
x3 : dfff800000000000 x2 : 0000000000000000 
x1 : 0000000000000000 x0 : ffff00002f050000 
Call trace:
 refcount_warn_saturate+0x108/0x1a0 lib/refcount.c:25
 __refcount_add include/linux/refcount.h:199 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 kref_get include/linux/kref.h:45 [inline]
 j1939_netdev_start+0x7bc/0x900 net/can/j1939/main.c:271
 j1939_sk_bind+0x2c8/0xd30 net/can/j1939/socket.c:479
 __sys_bind+0x16c/0x1d0 net/socket.c:1637
 __do_sys_bind net/socket.c:1648 [inline]
 __se_sys_bind net/socket.c:1646 [inline]
 __arm64_sys_bind+0x6c/0xa0 net/socket.c:1646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x6c/0x260 arch/arm64/kernel/syscall.c:52
 el0_svc_common.constprop.0+0xc4/0x1e4 arch/arm64/kernel/syscall.c:145
 do_el0_svc_compat+0x40/0x7c arch/arm64/kernel/syscall.c:190
 el0_svc_compat+0x24/0x3c arch/arm64/kernel/entry-common.c:500
 el0_sync_compat_handler+0x90/0x140 arch/arm64/kernel/entry-common.c:509
 el0_sync_compat+0x190/0x1c0 arch/arm64/kernel/entry.S:752
irq event stamp: 2186
hardirqs last  enabled at (2185): [<ffff800014431bcc>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last  enabled at (2185): [<ffff800014431bcc>] _raw_spin_unlock_irq+0x78/0x15c kernel/locking/spinlock.c:199
hardirqs last disabled at (2186): [<ffff800014410394>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:241
softirqs last  enabled at (2176): [<ffff8000100109e0>] _stext+0x9e0/0x1084
softirqs last disabled at (2123): [<ffff80001015ced4>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
softirqs last disabled at (2123): [<ffff80001015ced4>] invoke_softirq kernel/softirq.c:440 [inline]
softirqs last disabled at (2123): [<ffff80001015ced4>] __irq_exit_rcu+0x494/0x550 kernel/softirq.c:637
---[ end trace d54046d4d9a1d560 ]---