==================================================================
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 ffff000107906018 by task kworker/u8:5/257

CPU: 0 UID: 0 PID: 257 Comm: kworker/u8:5 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Workqueue: writeback wb_workfn (flush-7:1)
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:0x6812 pfn:0x147906
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000006812 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000107905f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff000107905f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff000107906000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff000107906080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff000107906100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
kworker/u8:5: attempt to access beyond end of device
loop6: rw=2049, sector=45096, nr_sectors = 24 limit=40427
CPU: 1 UID: 0 PID: 257 Comm: kworker/u8:5 Tainted: G    B        L      syzkaller #0 PREEMPT 
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Workqueue: writeback wb_workfn (flush-7:6)
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
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 f2fs_handle_critical_error+0x34c/0x4b8 fs/f2fs/super.c:4641
 f2fs_stop_checkpoint+0x5c/0x70 fs/f2fs/checkpoint.c:35
 f2fs_write_end_io+0x770/0xa78 fs/f2fs/data.c:351
 bio_endio+0x8d4/0x910 block/bio.c:1675
 submit_bio_noacct+0xd44/0x186c block/blk-core.c:886
 submit_bio+0x3b4/0x550 block/blk-core.c:921
 f2fs_submit_write_bio+0x124/0x324 fs/f2fs/data.c:525
 __submit_merged_bio+0x224/0x6d4 fs/f2fs/data.c:540
 __f2fs_submit_merged_write fs/f2fs/data.c:635 [inline]
 __submit_merged_write_cond+0x250/0x4ac fs/f2fs/data.c:657
 f2fs_submit_merged_write_cond fs/f2fs/data.c:674 [inline]
 f2fs_write_cache_pages fs/f2fs/data.c:3189 [inline]
 __f2fs_write_data_pages fs/f2fs/data.c:3285 [inline]
 f2fs_write_data_pages+0x1dd4/0x2878 fs/f2fs/data.c:3314
 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
F2FS-fs (loop6): Stopped filesystem due to reason: 3
CPU: 1 UID: 0 PID: 257 Comm: kworker/u8:5 Tainted: G    B        L      syzkaller #0 PREEMPT 
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Workqueue: writeback wb_workfn (flush-7:6)
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
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 f2fs_handle_critical_error+0x34c/0x4b8 fs/f2fs/super.c:4641
 f2fs_stop_checkpoint+0x5c/0x70 fs/f2fs/checkpoint.c:35
 f2fs_write_end_io+0x770/0xa78 fs/f2fs/data.c:351
 bio_endio+0x8d4/0x910 block/bio.c:1675
 submit_bio_noacct+0xd44/0x186c block/blk-core.c:886
 submit_bio+0x3b4/0x550 block/blk-core.c:921
 f2fs_submit_write_bio+0x124/0x324 fs/f2fs/data.c:525
 __submit_merged_bio+0x224/0x6d4 fs/f2fs/data.c:540
 __f2fs_submit_merged_write fs/f2fs/data.c:635 [inline]
 __submit_merged_write_cond+0x250/0x4ac fs/f2fs/data.c:657
 f2fs_submit_merged_write_cond fs/f2fs/data.c:674 [inline]
 f2fs_write_cache_pages fs/f2fs/data.c:3189 [inline]
 __f2fs_write_data_pages fs/f2fs/data.c:3285 [inline]
 f2fs_write_data_pages+0x1dd4/0x2878 fs/f2fs/data.c:3314
 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
F2FS-fs (loop6): Stopped filesystem due to reason: 3
CPU: 1 UID: 0 PID: 257 Comm: kworker/u8:5 Tainted: G    B        L      syzkaller #0 PREEMPT 
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Workqueue: writeback wb_workfn (flush-7:6)
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
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 f2fs_handle_critical_error+0x34c/0x4b8 fs/f2fs/super.c:4641
 f2fs_stop_checkpoint+0x5c/0x70 fs/f2fs/checkpoint.c:35
 f2fs_write_end_io+0x770/0xa78 fs/f2fs/data.c:351
 bio_endio+0x8d4/0x910 block/bio.c:1675
 submit_bio_noacct+0xd44/0x186c block/blk-core.c:886
 submit_bio+0x3b4/0x550 block/blk-core.c:921
 f2fs_submit_write_bio+0x124/0x324 fs/f2fs/data.c:525
 __submit_merged_bio+0x224/0x6d4 fs/f2fs/data.c:540
 __f2fs_submit_merged_write fs/f2fs/data.c:635 [inline]
 __submit_merged_write_cond+0x250/0x4ac fs/f2fs/data.c:657
 f2fs_submit_merged_write_cond fs/f2fs/data.c:674 [inline]
 f2fs_write_cache_pages fs/f2fs/data.c:3189 [inline]
 __f2fs_write_data_pages fs/f2fs/data.c:3285 [inline]
 f2fs_write_data_pages+0x1dd4/0x2878 fs/f2fs/data.c:3314
 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
F2FS-fs (loop6): Stopped filesystem due to reason: 3