================================================================== BUG: KASAN: use-after-free in ext4_search_dir+0xf2/0x1b0 fs/ext4/namei.c:1543 Read of size 1 at addr ffff88803fc6ba58 by task syz-executor.4/5590 CPU: 0 PID: 5590 Comm: syz-executor.4 Not tainted 6.6.0-rc3-syzkaller-00044-g633b47cb009d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __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:364 [inline] print_report+0x163/0x540 mm/kasan/report.c:475 kasan_report+0x175/0x1b0 mm/kasan/report.c:588 ext4_search_dir+0xf2/0x1b0 fs/ext4/namei.c:1543 ext4_find_inline_entry+0x4ba/0x5e0 fs/ext4/inline.c:1694 __ext4_find_entry+0x2b4/0x1b30 fs/ext4/namei.c:1616 ext4_lookup_entry fs/ext4/namei.c:1771 [inline] ext4_lookup+0x17a/0x750 fs/ext4/namei.c:1839 lookup_open fs/namei.c:3473 [inline] open_last_lookups fs/namei.c:3563 [inline] path_openat+0x11f1/0x3180 fs/namei.c:3793 do_filp_open+0x234/0x490 fs/namei.c:3823 do_sys_openat2+0x13e/0x1d0 fs/open.c:1422 do_sys_open fs/open.c:1437 [inline] __do_sys_creat fs/open.c:1513 [inline] __se_sys_creat fs/open.c:1507 [inline] __x64_sys_creat+0x123/0x160 fs/open.c:1507 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 RIP: 0033:0x7f378207cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3782d250c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f378219c1f0 RCX: 00007f378207cae9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000e00 RBP: 00007f37820c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f378219c1f0 R15: 00007ffed35d97e8 The buggy address belongs to the physical page: page:ffffea0000ff1ac0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x3fc6b 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 5425, tgid 5424 (syz-executor.4), ts 179039568158, free_ts 180349448066 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0x31db/0x3360 mm/page_alloc.c:3170 __alloc_pages+0x255/0x670 mm/page_alloc.c:4426 __folio_alloc+0x13/0x30 mm/page_alloc.c:4458 vma_alloc_folio+0x48a/0x9a0 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+0x2376/0x62b0 mm/memory.c:5284 do_user_addr_fault arch/x86/mm/fault.c:1364 [inline] handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x455/0x860 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:1136 [inline] free_unref_page_prepare+0x8c3/0x9f0 mm/page_alloc.c:2312 free_unref_page_list+0x596/0x830 mm/page_alloc.c:2451 release_pages+0x2113/0x23f0 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+0x34c/0x4e0 mm/mmu_gather.c:300 tlb_finish_mmu+0xd4/0x1f0 mm/mmu_gather.c:392 unmap_region+0x300/0x350 mm/mmap.c:2318 do_vmi_align_munmap+0x121e/0x1850 mm/mmap.c:2555 do_vmi_munmap+0x24d/0x2d0 mm/mmap.c:2623 __vm_munmap+0x230/0x450 mm/mmap.c:2908 __do_sys_munmap mm/mmap.c:2925 [inline] __se_sys_munmap mm/mmap.c:2922 [inline] __x64_sys_munmap+0x69/0x80 mm/mmap.c:2922 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: ffff88803fc6b900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803fc6b980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88803fc6ba00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88803fc6ba80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803fc6bb00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================