==================================================================
BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:841 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0x8dc/0xa8c fs/ext4/extents.c:956
Read of size 4 at addr ffff0000e3980018 by task kworker/u8:2/41

CPU: 1 UID: 0 PID: 41 Comm: kworker/u8:2 Not tainted 6.16.0-rc5-syzkaller-gec4801305969 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn (flush-7:2)
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0xa8/0x254 mm/kasan/report.c:408
 print_report+0x68/0x84 mm/kasan/report.c:521
 kasan_report+0xb0/0x110 mm/kasan/report.c:634
 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380
 ext4_ext_binsearch fs/ext4/extents.c:841 [inline]
 ext4_find_extent+0x8dc/0xa8c fs/ext4/extents.c:956
 ext4_ext_map_blocks+0x258/0x5494 fs/ext4/extents.c:4208
 ext4_map_create_blocks fs/ext4/inode.c:609 [inline]
 ext4_map_blocks+0x708/0x1434 fs/ext4/inode.c:813
 mpage_map_one_extent fs/ext4/inode.c:2348 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2401 [inline]
 ext4_do_writepages+0x196c/0x32b0 fs/ext4/inode.c:2863
 ext4_writepages+0x178/0x2a0 fs/ext4/inode.c:2953
 do_writepages+0x270/0x468 mm/page-writeback.c:2636
 __writeback_single_inode+0x15c/0x13e8 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x558/0xe38 fs/fs-writeback.c:1976
 wb_writeback+0x3cc/0xd70 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x338/0xdc0 fs/fs-writeback.c:2343
 process_one_work+0x7e8/0x155c kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x958/0xed8 kernel/workqueue.c:3402
 kthread+0x5fc/0x75c kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:843

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xb7c pfn:0x123980
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffdffc38e5fc8 fffffdffc38e6048 0000000000000000
raw: 0000000000000b7c 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e397ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e397ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000e3980000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff0000e3980080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e3980100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28
EXT4-fs (loop2): This should not happen!! Data will be lost

EXT4-fs (loop2): Total free blocks count 0
EXT4-fs (loop2): Free/Dirty block details
EXT4-fs (loop2): free_blocks=16
EXT4-fs (loop2): dirty_blocks=0
EXT4-fs (loop2): Block reservation details
EXT4-fs (loop2): i_reserved_data_blocks=0
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50