gfs2: fsid=loop0: Now mounting FS...
gfs2: not a GFS2 filesystem
==================================================================
BUG: KASAN: slab-out-of-bounds in gfs2_read_sb fs/gfs2/ops_fstype.c:332 [inline]
BUG: KASAN: slab-out-of-bounds in init_sb+0xc60/0xd80 fs/gfs2/ops_fstype.c:488
Write of size 8 at addr ffff888053f52cd0 by task syz-executor.0/17593

CPU: 1 PID: 17593 Comm: syz-executor.0 Not tainted 4.14.202-syzkaller #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+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_store8_noabort+0x68/0x70 mm/kasan/report.c:435
 gfs2_read_sb fs/gfs2/ops_fstype.c:332 [inline]
 init_sb+0xc60/0xd80 fs/gfs2/ops_fstype.c:488
gfs2: not a GFS2 filesystem
 fill_super+0x15b0/0x2310 fs/gfs2/ops_fstype.c:1139
 gfs2_mount+0x439/0x502 fs/gfs2/ops_fstype.c:1331
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4608aa
RSP: 002b:00007fed384bea88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fed384beb20 RCX: 00000000004608aa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fed384beae0
RBP: 00007fed384beae0 R08: 00007fed384beb20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020001340 R15: 0000000020000040

Allocated by task 17593:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 init_sbd fs/gfs2/ops_fstype.c:71 [inline]
 fill_super+0xb7/0x2310 fs/gfs2/ops_fstype.c:1060
 gfs2_mount+0x439/0x502 fs/gfs2/ops_fstype.c:1331
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 16698:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 fill_super+0x1489/0x2310 fs/gfs2/ops_fstype.c:1111
 gfs2_mount+0x439/0x502 fs/gfs2/ops_fstype.c:1331
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

The buggy address belongs to the object at ffff888053f51900
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 5072 bytes inside of
 8192-byte region [ffff888053f51900, ffff888053f53900)
The buggy address belongs to the page:
page:ffffea00014fd400 count:1 mapcount:0 mapping:ffff888053f51900 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffff888053f51900 0000000000000000 0000000100000001
raw: ffffea0001426c20 ffffea0001821f20 ffff88813fe08080 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888053f52b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888053f52c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888053f52c80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                 ^
 ffff888053f52d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888053f52d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================