KASAN: invalid-free in ceph_destroy_options

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 4762bcd4 Linux 4.14.153
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10d77c3ce00000
kernel config: https://syzkaller.appspot.com/x/.config?x=eb84bd8b9cc2ec66
dashboard link: https://syzkaller.appspot.com/bug?extid=190170a3d15199df2a22
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=140dd5aae00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+190170...@syzkaller.appspotmail.com

libceph: mon0 [d::]:6789 connect error
syz-executor.5 cpuset=syz5 mems_allowed=0-1
syz-executor.4 cpuset=syz4 mems_allowed=0-1
==================================================================
BUG: KASAN: double-free or invalid-free in ceph_destroy_options+0xd4/0x110
net/ceph/ceph_common.c:288

CPU: 1 PID: 11706 Comm: syz-executor.2 Not tainted 4.14.153 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x138/0x197 lib/dump_stack.c:53
print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
kasan_report_double_free+0x56/0x80 mm/kasan/report.c:333
kasan_slab_free+0xa7/0xc0 mm/kasan/kasan.c:514
__cache_free mm/slab.c:3496 [inline]
kfree+0xcc/0x270 mm/slab.c:3815
ceph_destroy_options+0xd4/0x110 net/ceph/ceph_common.c:288
ceph_mount+0xb6d/0x1709 fs/ceph/super.c:1009
mount_fs+0x97/0x2a1 fs/super.c:1237
vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2549 [inline]
do_mount+0x417/0x27d0 fs/namespace.c:2879
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xab/0x120 fs/namespace.c:3072
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a219
RSP: 002b:00007f4326c98c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a219
RDX: 0000000020000140 RSI: 00000000200000c0 RDI: 0000000020000500
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4326c996d4
R13: 00000000004c6d95 R14: 00000000004dc508 R15: 00000000ffffffff

Allocated by task 11706:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x45/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc mm/kasan/kasan.c:551 [inline]
kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
kmalloc include/linux/slab.h:488 [inline]
kmalloc_array include/linux/slab.h:606 [inline]
kcalloc include/linux/slab.h:618 [inline]
ceph_parse_options+0xfe/0xe80 net/ceph/ceph_common.c:352
parse_mount_options fs/ceph/super.c:466 [inline]
ceph_mount+0x3c1/0x1709 fs/ceph/super.c:998
mount_fs+0x97/0x2a1 fs/super.c:1237
vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2549 [inline]
do_mount+0x417/0x27d0 fs/namespace.c:2879
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xab/0x120 fs/namespace.c:3072
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 11706:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x45/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kfree+0xcc/0x270 mm/slab.c:3815
ceph_destroy_options+0xd4/0x110 net/ceph/ceph_common.c:288
ceph_destroy_client+0x9d/0xc0 net/ceph/ceph_common.c:671
create_fs_client fs/ceph/super.c:649 [inline]
ceph_mount+0xb46/0x1709 fs/ceph/super.c:1005
mount_fs+0x97/0x2a1 fs/super.c:1237
vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2549 [inline]
do_mount+0x417/0x27d0 fs/namespace.c:2879
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xab/0x120 fs/namespace.c:3072
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff888082e61340
which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 0 bytes inside of
8192-byte region [ffff888082e61340, ffff888082e63340)
The buggy address belongs to the page:
page:ffffea00020b9800 count:1 mapcount:0 mapping:ffff888082e61340 index:0x0
compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)
raw: 01fffc0000008100 ffff888082e61340 0000000000000000 0000000100000001
raw: ffffea0001f1df20 ffffea00020b9720 ffff8880aa802080 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff888082e61200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888082e61280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff888082e61300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
^
ffff888082e61380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888082e61400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches