==================================================================
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 ffff0000f57d00a0 by task kworker/u8:8/669

CPU: 1 UID: 0 PID: 669 Comm: kworker/u8:8 Not tainted 6.15.0-rc1-syzkaller-g2fe2b96c3818 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: writeback wb_workfn (flush-7:4)
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:408 [inline]
 print_report+0x198/0x550 mm/kasan/report.c:521
 kasan_report+0xd8/0x138 mm/kasan/report.c:634
 __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:519 [inline]
 ext4_map_blocks+0x710/0x15d0 fs/ext4/inode.c:705
 mpage_map_one_extent fs/ext4/inode.c:2223 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2276 [inline]
 ext4_do_writepages+0x1a14/0x31dc fs/ext4/inode.c:2738
 ext4_writepages+0x1bc/0x338 fs/ext4/inode.c:2828
 do_writepages+0x2f8/0x7c4 mm/page-writeback.c:2656
 __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+0x810/0x1638 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x97c/0xf08 kernel/workqueue.c:3400
 kthread+0x674/0x7dc kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xe90 pfn:0x1357d0
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 05ffc00000000000 fffffdffc3d54808 fffffdffc3d4cc08 0000000000000000
raw: 0000000000000e90 0000000000000004 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000f57cff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000f57d0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000f57d0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff0000f57d0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000f57d0180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50