================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:837 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xbe8/0xce0 fs/ext4/extents.c:953 Read of size 4 at addr ffff88807dbddbf0 by task kworker/u4:5/142 CPU: 1 PID: 142 Comm: kworker/u4:5 Not tainted 6.7.0-rc5-syzkaller-00042-g88035e5694a8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 ext4_ext_binsearch fs/ext4/extents.c:837 [inline] ext4_find_extent+0xbe8/0xce0 fs/ext4/extents.c:953 ext4_ext_map_blocks+0x26b/0x5ae0 fs/ext4/extents.c:4101 ext4_map_blocks+0x619/0x1770 fs/ext4/inode.c:621 mpage_map_one_extent fs/ext4/inode.c:2169 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2222 [inline] ext4_do_writepages+0x184e/0x3350 fs/ext4/inode.c:2685 ext4_writepages+0x30c/0x780 fs/ext4/inode.c:2774 do_writepages+0x1b4/0x690 mm/page-writeback.c:2553 __writeback_single_inode+0x158/0xe90 fs/fs-writeback.c:1625 writeback_sb_inodes+0x599/0x1080 fs/fs-writeback.c:1916 wb_writeback+0x2a5/0xaa0 fs/fs-writeback.c:2092 wb_do_writeback fs/fs-writeback.c:2239 [inline] wb_workfn+0x29c/0xfe0 fs/fs-writeback.c:2279 process_one_work+0x886/0x15d0 kernel/workqueue.c:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2781 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 The buggy address belongs to the physical page: page:ffffea0001f6f740 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x7dbdd flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() 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 4923, tgid 4923 (sshd), ts 47437741430, free_ts 47534633734 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1544 [inline] get_page_from_freelist+0xa25/0x36d0 mm/page_alloc.c:3312 __alloc_pages+0x22e/0x2420 mm/page_alloc.c:4568 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 vma_alloc_folio+0xad/0x220 mm/mempolicy.c:2172 do_anonymous_page mm/memory.c:4172 [inline] do_pte_missing mm/memory.c:3729 [inline] handle_pte_fault mm/memory.c:5039 [inline] __handle_mm_fault+0xe07/0x3d70 mm/memory.c:5180 handle_mm_fault+0x47a/0xa10 mm/memory.c:5345 do_user_addr_fault+0x30b/0x1000 arch/x86/mm/fault.c:1364 handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x5d/0xc0 arch/x86/mm/fault.c:1561 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:1137 [inline] free_unref_page_prepare+0x4fa/0xaa0 mm/page_alloc.c:2347 free_unref_page_list+0xe6/0xb40 mm/page_alloc.c:2533 release_pages+0x32a/0x14f0 mm/swap.c:1042 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:98 tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu mm/mmu_gather.c:300 [inline] tlb_finish_mmu+0x14b/0x6f0 mm/mmu_gather.c:392 unmap_region.constprop.0+0x2e6/0x3b0 mm/mmap.c:2341 do_vmi_align_munmap+0xde6/0x1600 mm/mmap.c:2657 do_vmi_munmap+0x20e/0x450 mm/mmap.c:2725 __vm_munmap+0x144/0x390 mm/mmap.c:3012 __do_sys_munmap mm/mmap.c:3029 [inline] __se_sys_munmap mm/mmap.c:3026 [inline] __x64_sys_munmap+0x62/0x80 mm/mmap.c:3026 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Memory state around the buggy address: ffff88807dbdda80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807dbddb00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88807dbddb80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807dbddc00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807dbddc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================