EXT4-fs warning (device loop2): dx_probe:893: inode #2: comm syz.2.17: dx entry: limit 65535 != root limit 120 EXT4-fs warning (device loop2): dx_probe:966: inode #2: comm syz.2.17: Corrupt directory, running e2fsck is recommended ================================================================== BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry+0x7c2/0x970 fs/ext4/dir.c:85 Read of size 2 at addr ffff88812f294003 by task syz.2.17/374 CPU: 0 PID: 374 Comm: syz.2.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report_generic.c:349 __ext4_check_dir_entry+0x7c2/0x970 fs/ext4/dir.c:85 ext4_readdir+0x1315/0x3e10 fs/ext4/dir.c:261 iterate_dir+0x271/0x610 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xf2/0x250 fs/readdir.c:354 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354 x64_sys_call+0x15c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f032199ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe2a6d78a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f0321c15fa0 RCX: 00007f032199ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f0321a32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0321c15fac R14: 00007f0321c15fa0 R15: 00007f0321c15fa0 The buggy address belongs to the object at ffff88812f294000 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 3 bytes inside of 16-byte region [ffff88812f294000, ffff88812f294010) The buggy address belongs to the physical page: page:ffffea0004bca500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12f294 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100042480 raw: 0000000000000000 0000000080800080 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 374, tgid 374 (syz.2.17), ts 27118736912, free_ts 27110966533 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4585 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5929 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3d0 mm/slub.c:2020 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa0/0x1e0 mm/slab_common.c:958 kmemdup_nul+0x31/0xa0 mm/util.c:157 vfs_parse_fs_string fs/fs_context.c:178 [inline] generic_parse_monolithic+0x24d/0x360 fs/fs_context.c:224 parse_monolithic_mount_data+0x7a/0x90 fs/fs_context.c:689 do_new_mount+0x222/0xb30 fs/namespace.c:3077 path_mount+0x659/0xfc0 fs/namespace.c:3411 do_mount fs/namespace.c:3424 [inline] __do_sys_mount fs/namespace.c:3632 [inline] __se_sys_mount+0x320/0x390 fs/namespace.c:3609 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1580 [inline] free_pcp_prepare mm/page_alloc.c:1654 [inline] free_unref_page_prepare+0x7f8/0x800 mm/page_alloc.c:3620 free_unref_page_list+0x117/0x8c0 mm/page_alloc.c:3771 release_pages+0xc93/0xcf0 mm/swap.c:1053 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:316 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu mm/mmu_gather.c:261 [inline] tlb_finish_mmu+0x1aa/0x370 mm/mmu_gather.c:361 unmap_region+0x2b7/0x320 mm/mmap.c:2419 do_mas_align_munmap+0xbed/0x1320 mm/mmap.c:2693 do_mas_munmap+0x241/0x2b0 mm/mmap.c:2751 __vm_munmap+0x1bd/0x330 mm/mmap.c:3050 __do_sys_munmap mm/mmap.c:3076 [inline] __se_sys_munmap mm/mmap.c:3072 [inline] __x64_sys_munmap+0x6b/0x80 mm/mmap.c:3072 x64_sys_call+0x8a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88812f293f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88812f293f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88812f294000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88812f294080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88812f294100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== EXT4-fs error (device loop2): ext4_readdir:263: inode #2: block 3: comm syz.2.17: path /0/file0: bad entry in directory: rec_len is smaller than minimal - offset=1023, inode=255, rec_len=0, size=1024 fake=0