EXT4-fs error (device loop0): ext4_fill_super:4365: inode #2: comm syz-executor.0: iget: root inode unallocated
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BUG: KASAN: use-after-free in memcpy include/linux/string.h:376 [inline]
BUG: KASAN: use-after-free in ext4_write_inline_data+0x2ae/0x380 fs/ext4/inline.c:251
Write of size 70 at addr ffff8880af9ab016 by task syz-executor.3/432

CPU: 1 PID: 432 Comm: syz-executor.3 Not tainted 4.14.232-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+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report+0x6f/0x80 mm/kasan/report.c:409
 memcpy+0x35/0x50 mm/kasan/kasan.c:303
 memcpy include/linux/string.h:376 [inline]
 ext4_write_inline_data+0x2ae/0x380 fs/ext4/inline.c:251
 ext4_write_inline_data_end+0x1d3/0x490 fs/ext4/inline.c:760
 ext4_write_end+0x18d/0xca0 fs/ext4/inode.c:1422
EXT4-fs (loop0): get root inode failed
 ext4_da_write_end+0x6da/0x8e0 fs/ext4/inode.c:3177
 generic_perform_write+0x268/0x420 mm/filemap.c:3066
EXT4-fs (loop0): mount failed
print_req_error: I/O error, dev loop1, sector 0
 __generic_file_write_iter+0x227/0x590 mm/filemap.c:3180
 ext4_file_write_iter+0x276/0xd20 fs/ext4/file.c:270
 call_write_iter include/linux/fs.h:1778 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x44c/0x630 fs/read_write.c:482
 vfs_write+0x17f/0x4d0 fs/read_write.c:544
 SYSC_write fs/read_write.c:590 [inline]
 SyS_write+0xf2/0x210 fs/read_write.c:582
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4665f9
RSP: 002b:00007f1ad4dcf188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 0000000000000082 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffe103d042f R14: 00007f1ad4dcf300 R15: 0000000000022000

Allocated by task 7984:
 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+0x124/0x3c0 mm/slab.c:3552
 copy_fs_struct+0x43/0x2d0 fs/fs_struct.c:113
 copy_fs kernel/fork.c:1281 [inline]
 copy_process.part.0+0x3da8/0x71c0 kernel/fork.c:1781
 copy_process kernel/fork.c:1605 [inline]
 _do_fork+0x184/0xc80 kernel/fork.c:2091
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 32254:
 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]
 kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
 free_fs_struct fs/fs_struct.c:91 [inline]
 exit_fs+0x113/0x160 fs/fs_struct.c:107
 do_exit+0xa20/0x2850 kernel/exit.c:864
 do_group_exit+0x100/0x2e0 kernel/exit.c:965
 SYSC_exit_group kernel/exit.c:976 [inline]
 SyS_exit_group+0x19/0x20 kernel/exit.c:974
 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 ffff8880af9ab000
 which belongs to the cache fs_cache of size 144
The buggy address is located 22 bytes inside of
 144-byte region [ffff8880af9ab000, ffff8880af9ab090)
The buggy address belongs to the page:
page:ffffea0002be6ac0 count:1 mapcount:0 mapping:ffff8880af9ab000 index:0xffff8880af9abd00
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff8880af9ab000 ffff8880af9abd00 000000010000000d
raw: ffffea0002bfeb60 ffffea00024eb560 ffff88823f830ac0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880af9aaf00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
 ffff8880af9aaf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880af9ab000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880af9ab080: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880af9ab100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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