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BUG: KASAN: use-after-free in memset include/linux/string.h:344 [inline]
BUG: KASAN: use-after-free in __ext4_expand_extra_isize+0x1ab/0x290 fs/ext4/inode.c:5921
Write of size 2528 at addr ffff8880644ee7a0 by task syz-executor.5/8838

CPU: 1 PID: 8838 Comm: syz-executor.5 Not tainted 5.3.0+ #0
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x17 mm/kasan/common.c:634
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
 memset+0x24/0x40 mm/kasan/common.c:105
 memset include/linux/string.h:344 [inline]
 __ext4_expand_extra_isize+0x1ab/0x290 fs/ext4/inode.c:5921
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5973 [inline]
 ext4_mark_inode_dirty+0x74e/0x9b0 fs/ext4/inode.c:6049
 ext4_dirty_inode+0x8f/0xc0 fs/ext4/inode.c:6083
 __mark_inode_dirty+0x68e/0x1300 fs/fs-writeback.c:2250
 generic_update_time+0x21c/0x370 fs/inode.c:1667
 update_time fs/inode.c:1683 [inline]
 touch_atime+0x23c/0x2a0 fs/inode.c:1754
 file_accessed include/linux/fs.h:2197 [inline]
 iterate_dir+0x36d/0x5e0 fs/readdir.c:56
 __do_sys_getdents fs/readdir.c:231 [inline]
 __se_sys_getdents fs/readdir.c:212 [inline]
 __x64_sys_getdents+0x226/0x3c0 fs/readdir.c:212
 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457d7b
Code: 02 74 b6 31 f6 eb b9 0f 1f 84 00 00 00 00 00 41 57 41 56 48 63 ff 41 55 41 54 b8 4e 00 00 00 55 53 48 89 f3 48 83 ec 08 0f 05 <48> 3d 00 f0 ff ff 77 55 4c 8d 24 06 49 89 c5 4c 39 e6 73 33 90 0f
RSP: 002b:00007ffdb7e10620 EFLAGS: 00000202 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 000055555738c9b0 RCX: 0000000000457d7b
RDX: 0000000000008000 RSI: 000055555738c9b0 RDI: 0000000000000004
RBP: 000055555738c9b0 R08: 0000000000000000 R09: 000000000000000b
R10: 0000000000000005 R11: 0000000000000202 R12: ffffffffffffffd4
R13: 0000000000000016 R14: 0000000000000000 R15: 00007ffdb7e128b0

The buggy address belongs to the page:
page:ffffea0001913b80 refcount:2 mapcount:0 mapping:ffff8880a2d86b60 index:0x42c
def_blk_aops 
flags: 0x1fffc000000203a(referenced|dirty|lru|active|private)
raw: 01fffc000000203a ffffea0001911688 ffffea00021417c8 ffff8880a2d86b60
raw: 000000000000042c ffff888089b9b7e0 00000002ffffffff ffff888064922ac0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff888064922ac0

Memory state around the buggy address:
 ffff8880644eef00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880644eef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880644ef000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8880644ef080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880644ef100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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