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BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2621 [inline]
BUG: KASAN: use-after-free in ext4_ext_remove_space+0x3766/0x49a0 fs/ext4/extents.c:2958
Read of size 4 at addr ffff888069bdec18 by task syz-executor/3360

CPU: 1 PID: 3360 Comm: syz-executor Not tainted 6.3.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xf8/0x260 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:319 [inline]
 print_report+0x167/0x540 mm/kasan/report.c:430
 kasan_report+0x176/0x1b0 mm/kasan/report.c:536
 ext4_ext_rm_leaf fs/ext4/extents.c:2621 [inline]
 ext4_ext_remove_space+0x3766/0x49a0 fs/ext4/extents.c:2958
 ext4_ext_truncate+0x195/0x260 fs/ext4/extents.c:4416
 ext4_truncate+0xaba/0xed0 fs/ext4/inode.c:4197
 ext4_evict_inode+0xc99/0x1260 fs/ext4/inode.c:285
 evict+0x264/0x650 fs/inode.c:665
 do_unlinkat+0x4ae/0x870 fs/namei.c:4323
 __do_sys_unlink fs/namei.c:4364 [inline]
 __se_sys_unlink fs/namei.c:4362 [inline]
 __x64_sys_unlink+0x44/0x50 fs/namei.c:4362
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x46/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x73/0xdd
RIP: 0033:0x7ff74a58c717
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc26c06e18 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff74a58c717
RDX: 00007ffc26c06e40 RSI: 00007ffc26c06ed0 RDI: 00007ffc26c06ed0
RBP: 00007ffc26c06ed0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc26c07fc0
R13: 00007ff74a60e08c R14: 0000000000013132 R15: 00007ffc26c0a180
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001a6f780 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x69bde
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 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 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 3316, tgid 3316 (syz-executor), ts 71953267855, free_ts 72165630876
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x10f/0x130 mm/page_alloc.c:2545
 prep_new_page+0x28/0x2a0 mm/page_alloc.c:2552
 get_page_from_freelist+0x31c8/0x3320 mm/page_alloc.c:4325
 __alloc_pages+0x255/0x650 mm/page_alloc.c:5591
 __folio_alloc+0x13/0x40 mm/page_alloc.c:5623
 vma_alloc_folio+0x48b/0x9f0 mm/mempolicy.c:2244
 do_anonymous_page mm/memory.c:4052 [inline]
 handle_pte_fault mm/memory.c:4907 [inline]
 __handle_mm_fault mm/memory.c:5051 [inline]
 handle_mm_fault+0x266a/0x3fd0 mm/memory.c:5197
 do_user_addr_fault arch/x86/mm/fault.c:1407 [inline]
 handle_page_fault arch/x86/mm/fault.c:1498 [inline]
 exc_page_fault+0x51d/0x720 arch/x86/mm/fault.c:1554
 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:1453 [inline]
 free_pcp_prepare mm/page_alloc.c:1503 [inline]
 free_unref_page_prepare+0xcaa/0xd00 mm/page_alloc.c:3387
 free_unref_page_list+0x54b/0x7f0 mm/page_alloc.c:3528
 release_pages+0x19c3/0x1b80 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+0xe9/0x1d0 mm/mmu_gather.c:299
 tlb_finish_mmu+0xb6/0x1c0 mm/mmu_gather.c:391
 unmap_region+0x230/0x280 mm/mmap.c:2146
 do_vmi_align_munmap+0x91f/0xe80 mm/mmap.c:2395
 do_vmi_munmap+0x199/0x200 mm/mmap.c:2452
 __vm_munmap+0x1ee/0x2c0 mm/mmap.c:2731
 __do_sys_munmap mm/mmap.c:2756 [inline]
 __se_sys_munmap mm/mmap.c:2753 [inline]
 __x64_sys_munmap+0x5b/0x70 mm/mmap.c:2753
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x46/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x73/0xdd

Memory state around the buggy address:
 ffff888069bdeb00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888069bdeb80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888069bdec00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff888069bdec80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888069bded00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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