================================================================== BUG: KASAN: out-of-bounds in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1543 Read of size 1 at addr ffff88811ff8f900 by task syz.3.56/486 CPU: 1 PID: 486 Comm: syz.3.56 Not tainted 6.1.93-syzkaller-00002-gd02968a02321 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:348 ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1543 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1722 __ext4_find_entry+0x2b0/0x1af0 fs/ext4/namei.c:1616 ext4_lookup_entry fs/ext4/namei.c:1771 [inline] ext4_lookup+0x176/0x740 fs/ext4/namei.c:1839 lookup_one_qstr_excl+0x143/0x290 fs/namei.c:1604 filename_create+0x28e/0x530 fs/namei.c:3878 do_mkdirat+0xbd/0x450 fs/namei.c:4122 __do_sys_mkdirat fs/namei.c:4147 [inline] __se_sys_mkdirat fs/namei.c:4145 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4145 x64_sys_call+0x6c6/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9207b7c797 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 02 01 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:00007f92088f8e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f92088f8ef0 RCX: 00007f9207b7c797 RDX: 00000000000001ff RSI: 0000000020000080 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000080 R13: 00007f92088f8eb0 R14: 0000000000000000 R15: 0000000000000000 The buggy address belongs to the physical page: page:ffffea00047fe3c0 refcount:2 mapcount:0 mapping:ffff88810b62d130 index:0x23 pfn:0x11ff8f memcg:ffff88810033a000 aops:shmem_aops ino:2 dentry name:"messages" flags: 0x460000000008004e(referenced|uptodate|dirty|workingset|swapbacked|zone=1) raw: 460000000008004e 0000000000000000 dead000000000122 ffff88810b62d130 raw: 0000000000000023 0000000000000000 00000002ffffffff ffff88810033a000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 83, tgid 83 (syslogd), ts 28156469928, free_ts 26540974327 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2590 prep_new_page+0x1b/0x110 mm/page_alloc.c:2597 get_page_from_freelist+0x27ea/0x2870 mm/page_alloc.c:4425 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5714 __folio_alloc+0x15/0x40 mm/page_alloc.c:5746 __folio_alloc_node include/linux/gfp.h:245 [inline] folio_alloc include/linux/gfp.h:274 [inline] shmem_alloc_folio mm/shmem.c:1597 [inline] shmem_alloc_and_acct_folio+0x78c/0xa50 mm/shmem.c:1622 shmem_get_folio_gfp+0x12d4/0x24b0 mm/shmem.c:1951 shmem_get_folio mm/shmem.c:2082 [inline] shmem_write_begin+0x164/0x3a0 mm/shmem.c:2570 generic_perform_write+0x2f9/0x5c0 mm/filemap.c:3844 __generic_file_write_iter+0x174/0x3a0 mm/filemap.c:3972 generic_file_write_iter+0xb1/0x310 mm/filemap.c:4004 call_write_iter include/linux/fs.h:2274 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x902/0xeb0 fs/read_write.c:584 ksys_write+0x199/0x2c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:646 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1498 [inline] free_pcp_prepare mm/page_alloc.c:1572 [inline] free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3498 free_unref_page_list+0xf1/0x7b0 mm/page_alloc.c:3646 release_pages+0xf7f/0xfe0 mm/swap.c:1063 free_pages_and_swap_cache+0x8a/0xa0 mm/swap_state.c:315 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu+0xfe/0x1d0 mm/mmu_gather.c:261 zap_pte_range mm/memory.c:1545 [inline] zap_pmd_range mm/memory.c:1594 [inline] zap_pud_range mm/memory.c:1623 [inline] zap_p4d_range mm/memory.c:1644 [inline] unmap_page_range+0x22d1/0x2620 mm/memory.c:1665 unmap_single_vma mm/memory.c:1711 [inline] unmap_vmas+0x4e4/0x660 mm/memory.c:1751 exit_mmap+0x2e7/0xbe0 mm/mmap.c:3335 __mmput+0x95/0x310 kernel/fork.c:1298 mmput+0x56/0x170 kernel/fork.c:1321 exit_mm kernel/exit.c:566 [inline] do_exit+0xb29/0x2b80 kernel/exit.c:862 do_group_exit+0x21a/0x2d0 kernel/exit.c:1025 __do_sys_exit_group kernel/exit.c:1036 [inline] __se_sys_exit_group kernel/exit.c:1034 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1034 x64_sys_call+0x610/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88811ff8f800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811ff8f880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88811ff8f900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff88811ff8f980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811ff8fa00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== EXT4-fs error (device loop3): ext4_find_dest_de:2112: inode #12: block 7: comm syz.3.56: bad entry in directory: directory entry overrun - offset=0, inode=1793120026, rec_len=34652, size=56 fake=0 EXT4-fs (loop3): unmounting filesystem.