general protection fault in kernfs_add_one

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f02af7b0 Merge 4.14.143 into android-4.14
git tree: android-4.14
console output: https://syzkaller.appspot.com/x/log.txt?x=1160bace600000
kernel config: https://syzkaller.appspot.com/x/.config?x=4d9cf2fd50fd7015
dashboard link: https://syzkaller.appspot.com/bug?extid=f7b10f4ca96eb3bf104d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f7b10f...@syzkaller.appspotmail.com

binder_alloc: binder_alloc_mmap_handler: 10349 20ffd000-21000000 already
mapped failed -16
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN NOPTI
Modules linked in:
CPU: 1 PID: 10356 Comm: syz-executor.3 Not tainted 4.14.143+ #0
task: 000000006dec65a2 task.stack: 0000000011a288cd
RIP: 0010:kernfs_add_one+0x2c2/0x3a0 fs/kernfs/dir.c:794
RSP: 0018:ffff8881c8e5f8c8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000a75
RDX: 0000000000000001 RSI: ffffc90000732000 RDI: 0000000000000008
RBP: ffff8881c8e5f900 R08: 0000000000000001 R09: fffffbfff5b2fe71
R10: fffffbfff5b2fe70 R11: ffffffffad97f387 R12: ffff8881d68761c0
R13: ffff8881d68761c0 R14: 0000000000000000 R15: ffff8881d68761e8
FS: 00007f2e37dad700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2e37d6adb8 CR3: 00000001c84e6003 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kernfs_create_dir_ns+0xe5/0x130 fs/kernfs/dir.c:1008
sysfs_create_dir_ns+0xb7/0x1d0 fs/sysfs/dir.c:55
create_dir lib/kobject.c:71 [inline]
kobject_add_internal+0x27f/0x830 lib/kobject.c:229
kobject_add_varg lib/kobject.c:364 [inline]
kobject_add+0x135/0x1a0 lib/kobject.c:409
device_add+0x333/0x13a0 drivers/base/core.c:1809
input_register_device+0x605/0xb20 drivers/input/input.c:2144
uinput_create_device drivers/input/misc/uinput.c:324 [inline]
uinput_ioctl_handler.isra.0+0xa2a/0x1850 drivers/input/misc/uinput.c:839
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4598e9
RSP: 002b:00007f2e37dacc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2e37dad6d4
R13: 00000000004c4644 R14: 00000000004d89b8 R15: 00000000ffffffff
Code: 70 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 9a 00 00 00 48 b8 00 00 00
00 00 fc ff df 48 8b 5b 70 48 8d 7b 08 48 89 fa 48 c1 ea 03 <0f> b6 04 02
84 c0 74 04 3c 03 7e 6e f6 43 08 01 0f 85 09 fe ff
RIP: kernfs_add_one+0x2c2/0x3a0 fs/kernfs/dir.c:794 RSP: ffff8881c8e5f8c8
---[ end trace 5084a5f2a621b451 ]---


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.