==================================================================
BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:826 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0xba3/0xd80 fs/ext4/extents.c:945
Read of size 4 at addr ffff88814742401c by task kworker/u4:1/5836

CPU: 0 PID: 5836 Comm: kworker/u4:1 Tainted: G        W         5.10.161-syzkaller-00019-g416c4356f372 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3c0 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report+0x1a4/0x1f0 mm/kasan/report.c:436
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 ext4_ext_binsearch fs/ext4/extents.c:826 [inline]
 ext4_find_extent+0xba3/0xd80 fs/ext4/extents.c:945
 ext4_ext_map_blocks+0x219/0x3a30 fs/ext4/extents.c:4097
 ext4_map_blocks+0xa93/0x1ee0 fs/ext4/inode.c:638
 mpage_map_one_extent+0x1bd/0x680 fs/ext4/inode.c:2441
 mpage_map_and_submit_extent fs/ext4/inode.c:2494 [inline]
 ext4_writepages+0x15e9/0x3710 fs/ext4/inode.c:2862
 do_writepages+0x13a/0x280 mm/page-writeback.c:2358
 __writeback_single_inode+0xb8/0x6e0 fs/fs-writeback.c:1467
 writeback_sb_inodes+0x999/0x1700 fs/fs-writeback.c:1730
 wb_writeback+0x42f/0xc20 fs/fs-writeback.c:1905
 wb_do_writeback+0x222/0xbd0 fs/fs-writeback.c:2050
 wb_workfn+0xf8/0x3f0 fs/fs-writeback.c:2091
 process_one_work+0x726/0xc10 kernel/workqueue.c:2296
 worker_thread+0xb27/0x1550 kernel/workqueue.c:2442
 kthread+0x349/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:299

The buggy address belongs to the page:
page:ffffea00051d0900 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x147424
flags: 0x8000000000000000()
raw: 8000000000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x1101cca(GFP_HIGHUSER_MOVABLE|__GFP_WRITE), pid 21372, ts 2007195985845, free_ts 2007854638722
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2386 [inline]
 prep_new_page mm/page_alloc.c:2392 [inline]
 get_page_from_freelist+0x755/0x810 mm/page_alloc.c:4073
 __alloc_pages_nodemask+0x3b6/0x890 mm/page_alloc.c:5160
 __alloc_pages include/linux/gfp.h:529 [inline]
 __alloc_pages_node include/linux/gfp.h:542 [inline]
 alloc_pages_node include/linux/gfp.h:556 [inline]
 alloc_pages include/linux/gfp.h:575 [inline]
 __page_cache_alloc include/linux/pagemap.h:290 [inline]
 pagecache_get_page+0x567/0x850 mm/filemap.c:1848
 grab_cache_page_write_begin+0x5c/0xa0 mm/filemap.c:3418
 ext4_da_write_begin+0x5c2/0xf10 fs/ext4/inode.c:3056
 generic_perform_write+0x309/0x5b0 mm/filemap.c:3468
 ext4_buffered_write_iter+0x47c/0x610 fs/ext4/file.c:272
 ext4_file_write_iter+0x192/0x1c70 fs/ext4/file.c:689
 __kernel_write+0x5ad/0x9d0 fs/read_write.c:550
 dump_emit fs/coredump.c:849 [inline]
 dump_user_range+0x25b/0x3b0 fs/coredump.c:902
 elf_core_dump+0x3156/0x3cd0 fs/binfmt_elf.c:2287
 do_coredump+0x1f7c/0x2dc0 fs/coredump.c:811
 get_signal+0xdde/0x1440 kernel/signal.c:2774
 arch_do_signal+0x8e/0x650 arch/x86/kernel/signal.c:805
 exit_to_user_mode_loop+0xa3/0xe0 kernel/entry/common.c:161
 exit_to_user_mode_prepare kernel/entry/common.c:191 [inline]
 irqentry_exit_to_user_mode+0x56/0x80 kernel/entry/common.c:279
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1332 [inline]
 free_pcp_prepare+0x18c/0x1c0 mm/page_alloc.c:1406
 free_unref_page_prepare mm/page_alloc.c:3293 [inline]
 free_unref_page_list+0x11d/0x660 mm/page_alloc.c:3367
 release_pages+0xc24/0xc60 mm/swap.c:1082
 __pagevec_release+0x81/0xf0 mm/swap.c:1102
 pagevec_release include/linux/pagevec.h:88 [inline]
 truncate_inode_pages_range+0x9f8/0x1940 mm/truncate.c:367
 truncate_inode_pages mm/truncate.c:473 [inline]
 truncate_inode_pages_final+0xc1/0xd0 mm/truncate.c:524
 ext4_evict_inode+0x41f/0x1730 fs/ext4/inode.c:223
 evict+0x2a3/0x6c0 fs/inode.c:577
 iput_final fs/inode.c:1655 [inline]
 iput+0x61f/0x7d0 fs/inode.c:1681
 dentry_unlink_inode+0x2df/0x3d0 fs/dcache.c:374
 __dentry_kill+0x3e2/0x5d0 fs/dcache.c:579
 dentry_kill+0xc0/0x2a0 fs/dcache.c:692
 dput+0x175/0x320 fs/dcache.c:878
 __fput+0x540/0x7c0 fs/file_table.c:294
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x147/0x1b0 kernel/task_work.c:154

Memory state around the buggy address:
 ffff888147423f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888147423f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888147424000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff888147424080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888147424100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop3): ext4_map_blocks:718: inode #19: block 761621556: comm kworker/u4:1: lblock 0 mapped to illegal pblock 761621556 (length 64)
EXT4-fs (loop3): Delayed block allocation failed for inode 19 at logical offset 0 with max blocks 64 with error 117
EXT4-fs (loop3): This should not happen!! Data will be lost