CVE-2026-97438

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> fs/ntfs3: validate index entry key bounds<br /> <br /> [BUG]<br /> A malformed NTFS directory index entry can advertise a key_size larger<br /> than the bytes actually present in its NTFS_DE payload. Directory lookup<br /> then passes that malformed key to cmp_fnames(), which can read past the<br /> end of the kmalloc&amp;#39;ed index buffer.<br /> <br /> BUG: KASAN: slab-out-of-bounds in fname_full_size fs/ntfs3/ntfs.h:590 [inline]<br /> BUG: KASAN: slab-out-of-bounds in cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46<br /> Read of size 1 at addr ffff88801c313018 by task syz.6.3365/9279<br /> <br /> Call Trace:<br /> __dump_stack lib/dump_stack.c:94 [inline]<br /> dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120<br /> print_address_description mm/kasan/report.c:378 [inline]<br /> print_report+0xd1/0x650 mm/kasan/report.c:482<br /> kasan_report+0xfb/0x140 mm/kasan/report.c:595<br /> __asan_report_load1_noabort+0x14/0x30 mm/kasan/report_generic.c:378<br /> fname_full_size fs/ntfs3/ntfs.h:590 [inline]<br /> cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46<br /> hdr_find_e.isra.0+0x3ed/0x670 fs/ntfs3/index.c:762<br /> indx_find+0x4b5/0x900 fs/ntfs3/index.c:1186<br /> dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254<br /> ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85<br /> __lookup_slow+0x241/0x450 fs/namei.c:1816<br /> lookup_slow fs/namei.c:1833 [inline]<br /> walk_component+0x31c/0x570 fs/namei.c:2151<br /> link_path_walk+0x592/0xd60 fs/namei.c:2519<br /> path_lookupat+0x138/0x660 fs/namei.c:2675<br /> filename_lookup+0x1f3/0x560 fs/namei.c:2705<br /> filename_setxattr+0xad/0x1c0 fs/xattr.c:660<br /> path_setxattrat+0x1d8/0x280 fs/xattr.c:713<br /> __do_sys_lsetxattr fs/xattr.c:754 [inline]<br /> __se_sys_lsetxattr fs/xattr.c:750 [inline]<br /> __x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750<br /> ...<br /> <br /> Allocated by task 9279:<br /> kasan_save_stack+0x39/0x70 mm/kasan/common.c:56<br /> kasan_save_track+0x14/0x40 mm/kasan/common.c:77<br /> kasan_save_alloc_info+0x37/0x60 mm/kasan/generic.c:573<br /> poison_kmalloc_redzone mm/kasan/common.c:400 [inline]<br /> __kasan_kmalloc+0xc3/0xd0 mm/kasan/common.c:417<br /> kasan_kmalloc include/linux/kasan.h:262 [inline]<br /> __do_kmalloc_node mm/slub.c:5650 [inline]<br /> __kmalloc_noprof+0x2bd/0x900 mm/slub.c:5662<br /> kmalloc_noprof include/linux/slab.h:961 [inline]<br /> indx_read+0x41d/0xad0 fs/ntfs3/index.c:1059<br /> indx_find+0x447/0x900 fs/ntfs3/index.c:1179<br /> dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254<br /> ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85<br /> __lookup_slow+0x241/0x450 fs/namei.c:1816<br /> lookup_slow fs/namei.c:1833 [inline]<br /> walk_component+0x31c/0x570 fs/namei.c:2151<br /> link_path_walk+0x592/0xd60 fs/namei.c:2519<br /> path_lookupat+0x138/0x660 fs/namei.c:2675<br /> filename_lookup+0x1f3/0x560 fs/namei.c:2705<br /> filename_setxattr+0xad/0x1c0 fs/xattr.c:660<br /> path_setxattrat+0x1d8/0x280 fs/xattr.c:713<br /> __do_sys_lsetxattr fs/xattr.c:754 [inline]<br /> __se_sys_lsetxattr fs/xattr.c:750 [inline]<br /> __x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750<br /> ...<br /> <br /> [CAUSE]<br /> The index-header validators only validated INDEX_HDR-level geometry.<br /> They did not walk each NTFS_DE to verify entry alignment, subnode<br /> layout, or that key_size fit inside the entry payload. They also<br /> allowed a last sentinel entry to carry a non-zero key_size.<br /> <br /> [FIX]<br /> Walk every NTFS_DE in ntfs3&amp;#39;s index-header validators and reject<br /> entries with invalid layout, mismatched subnode state, oversized<br /> key_size, or non-zero sentinel keys before lookup or log replay can<br /> consume them.