==================================================================
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 ffff000102069018 by task kworker/u8:13/2099

CPU: 0 UID: 0 PID: 2099 Comm: kworker/u8:13 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
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+0xa8/0x238 mm/kasan/report.c:378
 print_report+0x68/0x84 mm/kasan/report.c:482
 kasan_report+0xb0/0x110 mm/kasan/report.c:595
 __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+0x230/0x54a4 fs/ext4/extents.c:4208
 ext4_map_create_blocks fs/ext4/inode.c:613 [inline]
 ext4_map_blocks+0x784/0x1548 fs/ext4/inode.c:816
 mpage_map_one_extent fs/ext4/inode.c:2380 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline]
 ext4_do_writepages+0x1bbc/0x3a18 fs/ext4/inode.c:2932
 ext4_writepages+0x178/0x2a0 fs/ext4/inode.c:3026
 do_writepages+0x270/0x468 mm/page-writeback.c:2598
 __writeback_single_inode+0x144/0x16b8 fs/fs-writeback.c:1737
 writeback_sb_inodes+0x73c/0x16b4 fs/fs-writeback.c:2030
 wb_writeback+0x3b4/0xd70 fs/fs-writeback.c:2216
 wb_do_writeback fs/fs-writeback.c:2363 [inline]
 wb_workfn+0x320/0xdc0 fs/fs-writeback.c:2403
 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x958/0xed8 kernel/workqueue.c:3421
 kthread+0x5fc/0x75c kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x204 pfn:0x142069
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffdffc4081a88 fffffdffc4081a08 0000000000000000
raw: 0000000000000204 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000102068f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff000102068f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff000102069000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff000102069080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff000102069100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
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