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BUG: KASAN: use-after-free in memset include/linux/string.h:337 [inline]
BUG: KASAN: use-after-free in __ext4_expand_extra_isize+0x16c/0x240 fs/ext4/inode.c:5923
EXT4-fs (sda1): re-mounted. Opts: debug_want_extra_isize=0x0000000000005183,
Write of size 20835 at addr ffff88805ab774a0 by task syz-executor5/7938

CPU: 0 PID: 7938 Comm: syz-executor5 Not tainted 5.0.0-rc4+ #51
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+0x1db/0x2d0 lib/dump_stack.c:113
EXT4-fs (sda1): EXT4-fs: inode_readahead_blks must be 0 or a power of 2 smaller than 2^31
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 memset+0x24/0x40 mm/kasan/common.c:113
 memset include/linux/string.h:337 [inline]
 __ext4_expand_extra_isize+0x16c/0x240 fs/ext4/inode.c:5923
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5975 [inline]
 ext4_mark_inode_dirty+0x827/0xb80 fs/ext4/inode.c:6051
 ext4_unlink+0xdf4/0x1210 fs/ext4/namei.c:3040
 vfs_unlink+0x2d8/0x500 fs/namei.c:3999
 do_unlinkat+0x52a/0x9e0 fs/namei.c:4062
 __do_sys_unlink fs/namei.c:4109 [inline]
 __se_sys_unlink fs/namei.c:4107 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4107
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457dd7
Code: 00 66 90 b8 58 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 0d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ed b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffce686de18 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000457dd7
RDX: 00007ffce686de30 RSI: 00007ffce686de30 RDI: 00007ffce686dec0
RBP: 00000000000007fd R08: 0000000000000000 R09: 000000000000000c
R10: 0000000000000006 R11: 0000000000000246 R12: 00007ffce686ef50
R13: 0000000001ffb940 R14: 0000000000000000 R15: 0000000000000005

The buggy address belongs to the page:
page:ffffea00016addc0 count:2 mapcount:0 mapping:ffff888219e4c518 index:0x42b
def_blk_aops 
flags: 0x1fffc000000203a(referenced|dirty|lru|active|private)
raw: 01fffc000000203a ffffea00016a9ec8 ffffea00016afd48 ffff888219e4c518
raw: 000000000000042b ffff8880950109d8 00000002ffffffff ffff888055c8a600
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff888055c8a600

Memory state around the buggy address:
 ffff88805ab7bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805ab7bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805ab7c000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88805ab7c080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805ab7c100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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