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BUG: KASAN: use-after-free in __ext4_expand_extra_isize fs/ext4/inode.c:5924 [inline]
BUG: KASAN: use-after-free in ext4_try_to_expand_extra_isize fs/ext4/inode.c:5976 [inline]
BUG: KASAN: use-after-free in ext4_mark_inode_dirty+0x5a5/0x700 fs/ext4/inode.c:6052
Write of size 992 at addr ffff88806b472ea0 by task syz-executor.2/21829

CPU: 0 PID: 21829 Comm: syz-executor.2 Not tainted 5.4.0-rc1 #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+0x1d8/0x2f8 lib/dump_stack.c:113
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 check_memory_region_inline mm/kasan/generic.c:182 [inline]
 check_memory_region+0x2cf/0x2e0 mm/kasan/generic.c:192
 memset+0x23/0x40 mm/kasan/common.c:105
 __ext4_expand_extra_isize fs/ext4/inode.c:5924 [inline]
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5976 [inline]
 ext4_mark_inode_dirty+0x5a5/0x700 fs/ext4/inode.c:6052
 ext4_ext_truncate+0x9d/0x1d0 fs/ext4/extents.c:4583
 ext4_truncate+0xac1/0xf70 fs/ext4/inode.c:4511
 ext4_evict_inode+0x116e/0x1670 fs/ext4/inode.c:289
 evict+0x2a1/0x6c0 fs/inode.c:574
 iput_final fs/inode.c:1563 [inline]
 iput+0x508/0x690 fs/inode.c:1589
 dentry_unlink_inode+0x2e0/0x3d0 fs/dcache.c:374
 __dentry_kill+0x3e2/0x5e0 fs/dcache.c:579
 dentry_kill fs/dcache.c:673 [inline]
 dput+0x460/0x6f0 fs/dcache.c:859
 path_put+0x39/0x60 fs/namei.c:482
 free_fs_struct fs/fs_struct.c:91 [inline]
 exit_fs+0xed/0x150 fs/fs_struct.c:108
 do_exit+0x59b/0x2190 kernel/exit.c:813
 do_group_exit+0x15c/0x2b0 kernel/exit.c:921
 get_signal+0x4ac/0x1d60 kernel/signal.c:2734
 do_signal+0x37/0x640 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x303/0x580 arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274
 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a29
Code: Bad RIP value.
RSP: 002b:00007f020f011cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000075bf28 RCX: 0000000000459a29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075bf28
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf2c
R13: 00007ffe88cbdacf R14: 00007f020f0129c0 R15: 000000000075bf2c

The buggy address belongs to the page:
page:ffffea0001ad1c80 refcount:2 mapcount:0 mapping:ffff888219efdae0 index:0x473
def_blk_aops 
flags: 0x1fffc000000203a(referenced|dirty|lru|active|private)
raw: 01fffc000000203a ffffea0001f93408 ffffea0002002388 ffff888219efdae0
raw: 0000000000000473 ffff888092d14540 00000002ffffffff ffff88805e0546c0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff88805e0546c0

Memory state around the buggy address:
 ffff88806b472f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88806b472f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88806b473000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88806b473080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806b473100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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