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BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:827 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0xbc4/0xdd0 fs/ext4/extents.c:946
Read of size 4 at addr ffff88807f73cc44 by task kworker/u4:3/155

CPU: 1 PID: 155 Comm: kworker/u4:3 Not tainted 5.15.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 ext4_ext_binsearch fs/ext4/extents.c:827 [inline]
 ext4_find_extent+0xbc4/0xdd0 fs/ext4/extents.c:946
 ext4_ext_map_blocks+0x2da/0x7630 fs/ext4/extents.c:4144
 ext4_map_blocks+0xa66/0x1c70 fs/ext4/inode.c:672
 mpage_map_one_extent fs/ext4/inode.c:2407 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2460 [inline]
 ext4_writepages+0x160e/0x3d10 fs/ext4/inode.c:2828
 do_writepages+0x481/0x730 mm/page-writeback.c:2386
 __writeback_single_inode+0x15b/0xe30 fs/fs-writeback.c:1647
 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930
 wb_writeback+0x451/0xc50 fs/fs-writeback.c:2104
 wb_do_writeback fs/fs-writeback.c:2247 [inline]
 wb_workfn+0x46c/0x1130 fs/fs-writeback.c:2288
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

The buggy address belongs to the page:
page:ffffea0001fdcf00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x7f73c
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001bd8f48 ffffea0001bd84c8 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 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 4012, ts 66815997918, free_ts 66806815357
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423
 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146
 do_cow_fault mm/memory.c:4253 [inline]
 do_fault mm/memory.c:4364 [inline]
 handle_pte_fault mm/memory.c:4620 [inline]
 __handle_mm_fault mm/memory.c:4755 [inline]
 handle_mm_fault+0x2597/0x5960 mm/memory.c:4853
 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline]
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
 release_pages+0x1bb9/0x1f40 mm/swap.c:963
 __pagevec_lru_add+0x1584/0x18d0 mm/swap.c:1056
 lru_cache_add+0x556/0x7e0 mm/swap.c:453
 wp_page_copy+0xec3/0x2070 mm/memory.c:3087
 handle_pte_fault mm/memory.c:4638 [inline]
 __handle_mm_fault mm/memory.c:4755 [inline]
 handle_mm_fault+0x2a3d/0x5960 mm/memory.c:4853
 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline]
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568

Memory state around the buggy address:
 ffff88807f73cb00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807f73cb80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88807f73cc00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88807f73cc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807f73cd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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