================================================================== BUG: KASAN: use-after-free in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1516 Read of size 1 at addr ffff88812115b900 by task syz-executor584/314 CPU: 1 PID: 314 Comm: syz-executor584 Not tainted 5.10.226-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:452 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1516 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1700 __ext4_find_entry+0x2b0/0x1990 fs/ext4/namei.c:1589 ext4_lookup_entry fs/ext4/namei.c:1744 [inline] ext4_lookup+0x3c6/0xaa0 fs/ext4/namei.c:1812 __lookup_hash+0x143/0x290 fs/namei.c:1541 filename_create+0x202/0x750 fs/namei.c:3608 user_path_create fs/namei.c:3665 [inline] do_mknodat+0x187/0x450 fs/namei.c:3729 __do_sys_mknod fs/namei.c:3768 [inline] __se_sys_mknod fs/namei.c:3766 [inline] __x64_sys_mknod+0x80/0x90 fs/namei.c:3766 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9f590d7629 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 1d 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:00007f9f59088168 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f9f5915f488 RCX: 00007f9f590d7629 RDX: 0000000000000703 RSI: 0000000000000000 RDI: 0000000020000000 RBP: 00007f9f5915f480 R08: 00007f9f590886c0 R09: 0000000000000000 R10: 00007f9f590886c0 R11: 0000000000000246 R12: 00007f9f5915f48c R13: 000000000000000b R14: 00007ffe5ea02ad0 R15: 00007ffe5ea02bb8 The buggy address belongs to the page: page:ffffea00048456c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12115b flags: 0x4000000000000000() raw: 4000000000000000 ffffea000484a588 ffffea0004855fc8 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 0x8100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|0x8000000), pid 318, ts 25828448379, free_ts 25830411606 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x166/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348 __alloc_pages include/linux/gfp.h:544 [inline] __alloc_pages_node include/linux/gfp.h:557 [inline] alloc_pages_node include/linux/gfp.h:571 [inline] alloc_pages include/linux/gfp.h:590 [inline] do_anonymous_page mm/memory.c:3935 [inline] handle_pte_fault+0x1782/0x3e30 mm/memory.c:4758 ___handle_speculative_fault mm/memory.c:5191 [inline] __handle_speculative_fault+0x1370/0x1e90 mm/memory.c:5240 handle_speculative_fault include/linux/mm.h:1838 [inline] do_user_addr_fault arch/x86/mm/fault.c:1285 [inline] handle_page_fault arch/x86/mm/fault.c:1428 [inline] exc_page_fault+0x234/0x5b0 arch/x86/mm/fault.c:1484 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336 free_unref_page_list+0x122/0xb20 mm/page_alloc.c:3443 release_pages+0xea0/0xef0 mm/swap.c:1103 free_pages_and_swap_cache+0x8a/0xa0 mm/swap_state.c:356 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:326 unmap_region+0x31c/0x370 mm/mmap.c:2810 __do_munmap+0x699/0x8c0 mm/mmap.c:3041 __vm_munmap mm/mmap.c:3064 [inline] __do_sys_munmap mm/mmap.c:3090 [inline] __se_sys_munmap+0x120/0x1a0 mm/mmap.c:3086 __x64_sys_munmap+0x5b/0x70 mm/mmap.c:3086 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff88812115b800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812115b880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88812115b900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88812115b980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812115ba00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop1): ext4_find_dest_de:2077: inode #12: block 7: comm syz-executor584: bad entry in directory: directory entry overrun - offset=0, inode=1793120026, rec_len=34652, size=56 fake=0