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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+0xbc4/0xdd0 fs/ext4/extents.c:953
Read of size 4 at addr ffff888066e6b454 by task syz-executor.0/5452

CPU: 0 PID: 5452 Comm: syz-executor.0 Not tainted 6.6.0-rc2-syzkaller-g2cf0f7156238 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x15f/0x540 mm/kasan/report.c:475
 kasan_report+0x171/0x1b0 mm/kasan/report.c:588
 ext4_ext_binsearch fs/ext4/extents.c:837 [inline]
 ext4_find_extent+0xbc4/0xdd0 fs/ext4/extents.c:953
 ext4_ext_map_blocks+0x2c7/0x7140 fs/ext4/extents.c:4101
 ext4_map_blocks+0xa2b/0x1cb0 fs/ext4/inode.c:621
 _ext4_get_block+0x234/0x6a0 fs/ext4/inode.c:763
 __block_write_begin_int+0x551/0x1a20 fs/buffer.c:2107
 block_page_mkwrite+0x2a1/0x4a0 fs/buffer.c:2625
 ext4_page_mkwrite+0x4d4/0x1210 fs/ext4/inode.c:6150
 do_page_mkwrite+0x197/0x470 mm/memory.c:2931
 wp_page_shared mm/memory.c:3291 [inline]
 do_wp_page+0xf83/0x4140 mm/memory.c:3376
 handle_pte_fault mm/memory.c:4994 [inline]
 __handle_mm_fault mm/memory.c:5119 [inline]
 handle_mm_fault+0x1c3c/0x6330 mm/memory.c:5284
 do_user_addr_fault arch/x86/mm/fault.c:1413 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x346/0x890 arch/x86/mm/fault.c:1561
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7ff875a5dcc7
Code: ce 48 ff c7 48 01 fe 48 8d 54 11 80 0f 1f 80 00 00 00 00 c5 fe 6f 0e c5 fe 6f 56 20 c5 fe 6f 5e 40 c5 fe 6f 66 60 48 83 ee 80 <c5> fd 7f 0f c5 fd 7f 57 20 c5 fd 7f 5f 40 c5 fd 7f 67 60 48 83 ef
RSP: 002b:00007ffd8ce29878 EFLAGS: 00010203
RAX: 0000000020003600 RBX: 00007ffd8ce29988 RCX: 0000000020003600
RDX: 00000000200036a9 RSI: 00007ff8756207b0 RDI: 0000000020003620
RBP: 0000000000000001 R08: 0000000000000000 R09: 00007ff875b9bf8c
R10: 00007ffd8ce299b0 R11: 0000000000000246 R12: 00007ff8756206f0
R13: fffffffffffffffe R14: 00007ff875600000 R15: 00007ff8756206f8
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00019b9ac0 refcount:1 mapcount:1 mapping:0000000000000000 index:0x7f44e25a0 pfn:0x66e6b
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea00019b6708 ffffea00019b92c8 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 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 5473, tgid 5473 (rm), ts 81383755741, free_ts 81403272605
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1d2/0x1f0 mm/page_alloc.c:1536
 prep_new_page mm/page_alloc.c:1543 [inline]
 get_page_from_freelist+0x31b7/0x3330 mm/page_alloc.c:3170
 __alloc_pages+0x251/0x660 mm/page_alloc.c:4426
 __folio_alloc+0xf/0x30 mm/page_alloc.c:4458
 vma_alloc_folio+0x486/0x990 mm/mempolicy.c:2259
 do_anonymous_page mm/memory.c:4110 [inline]
 do_pte_missing mm/memory.c:3667 [inline]
 handle_pte_fault mm/memory.c:4978 [inline]
 __handle_mm_fault mm/memory.c:5119 [inline]
 handle_mm_fault+0x2456/0x6330 mm/memory.c:5284
 do_user_addr_fault arch/x86/mm/fault.c:1413 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x346/0x890 arch/x86/mm/fault.c:1561
 asm_exc_page_fault+0x22/0x30 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:1136 [inline]
 free_unref_page_prepare+0x8ae/0x9d0 mm/page_alloc.c:2312
 free_unref_page_list+0x58e/0x830 mm/page_alloc.c:2451
 release_pages+0x26e2/0x2a00 mm/swap.c:1042
 tlb_batch_pages_flush mm/mmu_gather.c:98 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:293 [inline]
 tlb_flush_mmu+0x348/0x4d0 mm/mmu_gather.c:300
 tlb_finish_mmu+0xd0/0x1f0 mm/mmu_gather.c:392
 exit_mmap+0x4cf/0xc20 mm/mmap.c:3223
 __mmput+0x115/0x3c0 kernel/fork.c:1349
 exit_mm+0x21b/0x2f0 kernel/exit.c:567
 do_exit+0x9ab/0x2650 kernel/exit.c:861
 do_group_exit+0x202/0x2b0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1033
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff888066e6b300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888066e6b380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888066e6b400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff888066e6b480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888066e6b500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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