fuse: Bad value for 'user_id'
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 20466 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 20466 Comm: syz-executor.0 Not tainted 5.9.0-rc8-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+0x198/0x1fd lib/dump_stack.c:118
 panic+0x382/0x7fb kernel/panic.c:231
 __warn.cold+0x20/0x4b kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Code: 07 31 ff 89 de e8 a7 41 b6 fd 84 db 0f 85 36 ff ff ff e8 7a 45 b6 fd 48 c7 c7 00 71 d8 88 c6 05 a7 b4 94 07 01 e8 69 82 86 fd <0f> 0b e9 17 ff ff ff e8 5b 45 b6 fd 0f b6 1d 8c b4 94 07 31 ff 89
RSP: 0018:ffffc90008bd7d38 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff815f5a55 RDI: fffff5200117af99
RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8880ae520f8b
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88804b900000
R13: ffffc90008bd7e3c R14: ffffc90008bd7e48 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+0x580/0x6c0 net/can/j1939/main.c:277
 j1939_sk_bind+0x901/0xde0 net/can/j1939/socket.c:478
 __sys_bind+0x1e9/0x250 net/socket.c:1656
 __do_sys_bind net/socket.c:1667 [inline]
 __se_sys_bind net/socket.c:1665 [inline]
 __x64_sys_bind+0x6f/0xb0 net/socket.c:1665
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de29
Code: 0d b4 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f6e831cbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000c40 RCX: 000000000045de29
RDX: 0000000000000018 RSI: 0000000020000240 RDI: 0000000000000006
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 000000000169fb7f R14: 00007f6e831cc9c0 R15: 000000000118bf2c
Kernel Offset: disabled
Rebooting in 86400 seconds..