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BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:837 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0xbc8/0xde0 fs/ext4/extents.c:953
Read of size 4 at addr ffff8880835067e8 by task kworker/u4:1/12

CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.4.0-syzkaller-01312-gb19edac5992d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: writeback wb_workfn (flush-7:1)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:351 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:462
 kasan_report+0x176/0x1b0 mm/kasan/report.c:572
 ext4_ext_binsearch fs/ext4/extents.c:837 [inline]
 ext4_find_extent+0xbc8/0xde0 fs/ext4/extents.c:953
 ext4_ext_map_blocks+0x2d1/0x7210 fs/ext4/extents.c:4102
 ext4_map_blocks+0xa4c/0x1cf0 fs/ext4/inode.c:623
 mpage_map_one_extent fs/ext4/inode.c:2183 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2236 [inline]
 ext4_do_writepages+0x1670/0x3da0 fs/ext4/inode.c:2703
 ext4_writepages+0x203/0x3e0 fs/ext4/inode.c:2792
 do_writepages+0x3a6/0x670 mm/page-writeback.c:2551
 __writeback_single_inode+0x155/0xfa0 fs/fs-writeback.c:1603
 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894
 wb_writeback+0x458/0xc70 fs/fs-writeback.c:2068
 wb_do_writeback fs/fs-writeback.c:2211 [inline]
 wb_workfn+0x400/0xff0 fs/fs-writeback.c:2251
 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2408
 worker_thread+0xa63/0x1210 kernel/workqueue.c:2555
 kthread+0x2b8/0x350 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00020d4180 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x1 pfn:0x83506
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffff7f(buddy)
raw: 00fff00000000000 ffffea00020ea748 ffffea0002176248 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffff7f 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 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 17327, tgid 17325 (syz-executor.0), ts 689348390305, free_ts 689492700236
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1744
 prep_new_page mm/page_alloc.c:1751 [inline]
 get_page_from_freelist+0x320e/0x3390 mm/page_alloc.c:3523
 __alloc_pages+0x255/0x670 mm/page_alloc.c:4794
 __folio_alloc+0x13/0x30 mm/page_alloc.c:4826
 vma_alloc_folio+0x48a/0x9a0 mm/mempolicy.c:2240
 do_anonymous_page mm/memory.c:4085 [inline]
 do_pte_missing mm/memory.c:3645 [inline]
 handle_pte_fault mm/memory.c:4947 [inline]
 __handle_mm_fault mm/memory.c:5089 [inline]
 handle_mm_fault+0x2942/0x5860 mm/memory.c:5243
 do_user_addr_fault arch/x86/mm/fault.c:1349 [inline]
 handle_page_fault arch/x86/mm/fault.c:1534 [inline]
 exc_page_fault+0x274/0x910 arch/x86/mm/fault.c:1590
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1308 [inline]
 free_unref_page_prepare+0x903/0xa30 mm/page_alloc.c:2577
 free_unref_page_list+0x596/0x830 mm/page_alloc.c:2718
 release_pages+0x2193/0x2470 mm/swap.c:1042
 tlb_batch_pages_flush mm/mmu_gather.c:97 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
 tlb_flush_mmu+0x100/0x210 mm/mmu_gather.c:299
 tlb_finish_mmu+0xd4/0x1f0 mm/mmu_gather.c:391
 unmap_region+0x258/0x2a0 mm/mmap.c:2222
 do_vmi_align_munmap+0x120a/0x1900 mm/mmap.c:2465
 do_vmi_munmap+0x24a/0x2b0 mm/mmap.c:2527
 __vm_munmap+0x226/0x470 mm/mmap.c:2802
 __do_sys_munmap mm/mmap.c:2827 [inline]
 __se_sys_munmap mm/mmap.c:2824 [inline]
 __x64_sys_munmap+0x69/0x80 mm/mmap.c:2824
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff888083506680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888083506700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888083506780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                          ^
 ffff888083506800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888083506880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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