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BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:841 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0xae6/0xcc0 fs/ext4/extents.c:958
Read of size 4 at addr ffff8880131a530c by task kworker/u4:9/1087

CPU: 0 UID: 0 PID: 1087 Comm: kworker/u4:9 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 ext4_ext_binsearch fs/ext4/extents.c:841 [inline]
 ext4_find_extent+0xae6/0xcc0 fs/ext4/extents.c:958
 ext4_ext_map_blocks+0x283/0x58b0 fs/ext4/extents.c:4263
 ext4_map_create_blocks+0x11d/0x540 fs/ext4/inode.c:616
 ext4_map_blocks+0x7cd/0x11d0 fs/ext4/inode.c:809
 ext4_convert_unwritten_extents+0x2be/0x5f0 fs/ext4/extents.c:5031
 ext4_convert_unwritten_io_end_vec+0xff/0x170 fs/ext4/extents.c:5071
 ext4_end_io_end+0xc7/0x410 fs/ext4/page-io.c:200
 ext4_do_flush_completed_IO fs/ext4/page-io.c:291 [inline]
 ext4_end_io_rsv_work+0x26a/0x340 fs/ext4/page-io.c:306
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x6a pfn:0x131a5
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 000000000000006a 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 0x152c4a(GFP_NOFS|__GFP_HIGHMEM|__GFP_MOVABLE|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 1, tgid 1 (init), ts 28805532659, free_ts 82462650132
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2485
 alloc_frozen_pages_noprof mm/mempolicy.c:2556 [inline]
 alloc_pages_noprof+0xa8/0x190 mm/mempolicy.c:2576
 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2586
 filemap_alloc_folio_noprof+0x111/0x470 mm/filemap.c:1013
 ractl_alloc_folio mm/readahead.c:189 [inline]
 page_cache_ra_unbounded+0x39b/0xa50 mm/readahead.c:277
 do_page_cache_ra mm/readahead.c:334 [inline]
 page_cache_ra_order+0xaf2/0xeb0 mm/readahead.c:538
 filemap_readahead mm/filemap.c:2658 [inline]
 filemap_get_pages+0x897/0x1f10 mm/filemap.c:2704
 filemap_read+0x447/0x1230 mm/filemap.c:2800
 __kernel_read+0x504/0x9b0 fs/read_write.c:532
 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline]
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
 ima_calc_file_hash+0x12c3/0x17f0 security/integrity/ima/ima_crypto.c:568
 ima_collect_measurement+0x48b/0x930 security/integrity/ima/ima_api.c:294
 process_measurement+0x12cd/0x1c80 security/integrity/ima/ima_main.c:407
page last free pid 71 tgid 71 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 free_unref_folios+0xed5/0x16d0 mm/page_alloc.c:3040
 shrink_folio_list+0x2a0f/0x5290 mm/vmscan.c:1541
 evict_folios+0x4795/0x5880 mm/vmscan.c:4717
 try_to_shrink_lruvec+0xb62/0xfa0 mm/vmscan.c:4880
 shrink_one+0x25c/0x710 mm/vmscan.c:4925
 shrink_many mm/vmscan.c:4988 [inline]
 lru_gen_shrink_node mm/vmscan.c:5066 [inline]
 shrink_node+0x3197/0x3a90 mm/vmscan.c:6046
 kswapd_shrink_node mm/vmscan.c:6893 [inline]
 balance_pgdat mm/vmscan.c:7069 [inline]
 kswapd+0x1742/0x2e10 mm/vmscan.c:7342
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8880131a5200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880131a5280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880131a5300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff8880131a5380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880131a5400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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