------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 19906 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 19906 Comm: syz-executor.5 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:105 [inline]
 fixup_bug arch/x86/kernel/traps.c:100 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:197
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:216
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Code: 06 31 ff 89 de e8 c7 25 db fd 84 db 0f 85 36 ff ff ff e8 8a 24 db fd 48 c7 c7 a0 ce 72 88 c6 05 ac f3 ed 06 01 e8 bf 29 ac fd <0f> 0b e9 17 ff ff ff e8 6b 24 db fd 0f b6 1d 91 f3 ed 06 31 ff 89
RSP: 0018:ffffc9000859fd20 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000013627 RSI: ffffffff815d29a7 RDI: fffff520010b3f96
RBP: 0000000000000002 R08: ffff8880936a0100 R09: ffffed1015cc670d
R10: ffff8880ae633867 R11: ffffed1015cc670c R12: ffff888049774000
R13: ffff8880605c2000 R14: ffff888086ff6558 R15: 0000000000000118
 refcount_add include/linux/refcount.h:204 [inline]
 refcount_inc include/linux/refcount.h:241 [inline]
 kref_get include/linux/kref.h:45 [inline]
 j1939_netdev_start+0x520/0x640 net/can/j1939/main.c:277
 j1939_sk_bind+0x692/0x990 net/can/j1939/socket.c:469
 __sys_bind+0x20e/0x250 net/socket.c:1657
 __do_sys_bind net/socket.c:1668 [inline]
 __se_sys_bind net/socket.c:1666 [inline]
 __x64_sys_bind+0x6f/0xb0 net/socket.c:1666
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca69
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ff5b0fc1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 00000000004d9a80 RCX: 000000000045ca69
RDX: 0000000000000018 RSI: 0000000020000340 RDI: 0000000000000008
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000030 R14: 00000000004c2f4e R15: 00007ff5b0fc26d4
Kernel Offset: disabled
Rebooting in 86400 seconds..