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BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:840 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0x94c/0xb0c fs/ext4/extents.c:955
Read of size 4 at addr ffff0000dfa1f5a0 by task kworker/u8:10/2210

CPU: 1 UID: 0 PID: 2210 Comm: kworker/u8:10 Not tainted 6.13.0-rc3-syzkaller-g573067a5a685 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: writeback wb_workfn (flush-7:3)
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x198/0x538 mm/kasan/report.c:489
 kasan_report+0xd8/0x138 mm/kasan/report.c:602
 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380
 ext4_ext_binsearch fs/ext4/extents.c:840 [inline]
 ext4_find_extent+0x94c/0xb0c fs/ext4/extents.c:955
 ext4_ext_map_blocks+0x2b0/0x6600 fs/ext4/extents.c:4205
 ext4_map_create_blocks fs/ext4/inode.c:516 [inline]
 ext4_map_blocks+0x710/0x15d0 fs/ext4/inode.c:702
 mpage_map_one_extent fs/ext4/inode.c:2219 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2272 [inline]
 ext4_do_writepages+0x195c/0x318c fs/ext4/inode.c:2735
 ext4_writepages+0x198/0x308 fs/ext4/inode.c:2824
 do_writepages+0x304/0x7d0 mm/page-writeback.c:2702
 __writeback_single_inode+0x15c/0x15a4 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x650/0x1088 fs/fs-writeback.c:1976
 wb_writeback+0x3e0/0xe9c fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x38c/0x1048 fs/fs-writeback.c:2343
 process_one_work+0x7a8/0x15cc kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x97c/0xeec kernel/workqueue.c:3391
 kthread+0x288/0x310 kernel/kthread.c:389
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:00000000d3008c7f index:0xeb6 pfn:0x11fa1f
memcg:ffff0000d144c000
aops:shmem_aops ino:417 dentry name(?):"memfd:syzkaller"
flags: 0x5ffc0000002003c(referenced|uptodate|dirty|lru|swapbacked|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc0000002003c fffffdffc37e8788 fffffdffc37e8808 ffff0000d02ed888
raw: 0000000000000eb6 0000000000000000 00000001ffffffff ffff0000d144c000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000dfa1f480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000dfa1f500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000dfa1f580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                               ^
 ffff0000dfa1f600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000dfa1f680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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