In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: validate index entry key bounds
[BUG]
A malformed NTFS directory index entry can advertise a key_size larger
than the bytes actually present in its NTFS_DE payload. Directory lookup
then passes that malformed key to cmp_fnames(), which can read past the
end of the kmalloc'ed index buffer.
BUG: KASAN: slab-out-of-bounds in fname_full_size fs/ntfs3/ntfs.h:590 [inline]
BUG: KASAN: slab-out-of-bounds in cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46
Read of size 1 at addr ffff88801c313018 by task syz.6.3365/9279
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xd1/0x650 mm/kasan/report.c:482
kasan_report+0xfb/0x140 mm/kasan/report.c:595
__asan_report_load1_noabort+0x14/0x30 mm/kasan/report_generic.c:378
fname_full_size fs/ntfs3/ntfs.h:590 [inline]
cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46
hdr_find_e.isra.0+0x3ed/0x670 fs/ntfs3/index.c:762
indx_find+0x4b5/0x900 fs/ntfs3/index.c:1186
dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254
ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85
__lookup_slow+0x241/0x450 fs/namei.c:1816
lookup_slow fs/namei.c:1833 [inline]
walk_component+0x31c/0x570 fs/namei.c:2151
link_path_walk+0x592/0xd60 fs/namei.c:2519
path_lookupat+0x138/0x660 fs/namei.c:2675
filename_lookup+0x1f3/0x560 fs/namei.c:2705
filename_setxattr+0xad/0x1c0 fs/xattr.c:660
path_setxattrat+0x1d8/0x280 fs/xattr.c:713
__do_sys_lsetxattr fs/xattr.c:754 [inline]
__se_sys_lsetxattr fs/xattr.c:750 [inline]
__x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750
...
Allocated by task 9279:
kasan_save_stack+0x39/0x70 mm/kasan/common.c:56
kasan_save_track+0x14/0x40 mm/kasan/common.c:77
kasan_save_alloc_info+0x37/0x60 mm/kasan/generic.c:573
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xc3/0xd0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:262 [inline]
__do_kmalloc_node mm/slub.c:5650 [inline]
__kmalloc_noprof+0x2bd/0x900 mm/slub.c:5662
kmalloc_noprof include/linux/slab.h:961 [inline]
indx_read+0x41d/0xad0 fs/ntfs3/index.c:1059
indx_find+0x447/0x900 fs/ntfs3/index.c:1179
dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254
ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85
__lookup_slow+0x241/0x450 fs/namei.c:1816
lookup_slow fs/namei.c:1833 [inline]
walk_component+0x31c/0x570 fs/namei.c:2151
link_path_walk+0x592/0xd60 fs/namei.c:2519
path_lookupat+0x138/0x660 fs/namei.c:2675
filename_lookup+0x1f3/0x560 fs/namei.c:2705
filename_setxattr+0xad/0x1c0 fs/xattr.c:660
path_setxattrat+0x1d8/0x280 fs/xattr.c:713
__do_sys_lsetxattr fs/xattr.c:754 [inline]
__se_sys_lsetxattr fs/xattr.c:750 [inline]
__x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750
...
[CAUSE]
The index-header validators only validated INDEX_HDR-level geometry.
They did not walk each NTFS_DE to verify entry alignment, subnode
layout, or that key_size fit inside the entry payload. They also
allowed a last sentinel entry to carry a non-zero key_size.
[FIX]
Walk every NTFS_DE in ntfs3's index-header validators and reject
entries with invalid layout, mismatched subnode state, oversized
key_size, or non-zero sentinel keys before lookup or log replay can
consume them.
fs/ntfs3: validate index entry key bounds
[BUG]
A malformed NTFS directory index entry can advertise a key_size larger
than the bytes actually present in its NTFS_DE payload. Directory lookup
then passes that malformed key to cmp_fnames(), which can read past the
end of the kmalloc'ed index buffer.
BUG: KASAN: slab-out-of-bounds in fname_full_size fs/ntfs3/ntfs.h:590 [inline]
BUG: KASAN: slab-out-of-bounds in cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46
Read of size 1 at addr ffff88801c313018 by task syz.6.3365/9279
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xd1/0x650 mm/kasan/report.c:482
kasan_report+0xfb/0x140 mm/kasan/report.c:595
__asan_report_load1_noabort+0x14/0x30 mm/kasan/report_generic.c:378
fname_full_size fs/ntfs3/ntfs.h:590 [inline]
cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46
hdr_find_e.isra.0+0x3ed/0x670 fs/ntfs3/index.c:762
indx_find+0x4b5/0x900 fs/ntfs3/index.c:1186
dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254
ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85
__lookup_slow+0x241/0x450 fs/namei.c:1816
lookup_slow fs/namei.c:1833 [inline]
walk_component+0x31c/0x570 fs/namei.c:2151
link_path_walk+0x592/0xd60 fs/namei.c:2519
path_lookupat+0x138/0x660 fs/namei.c:2675
filename_lookup+0x1f3/0x560 fs/namei.c:2705
filename_setxattr+0xad/0x1c0 fs/xattr.c:660
path_setxattrat+0x1d8/0x280 fs/xattr.c:713
__do_sys_lsetxattr fs/xattr.c:754 [inline]
__se_sys_lsetxattr fs/xattr.c:750 [inline]
__x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750
...
Allocated by task 9279:
kasan_save_stack+0x39/0x70 mm/kasan/common.c:56
kasan_save_track+0x14/0x40 mm/kasan/common.c:77
kasan_save_alloc_info+0x37/0x60 mm/kasan/generic.c:573
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xc3/0xd0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:262 [inline]
__do_kmalloc_node mm/slub.c:5650 [inline]
__kmalloc_noprof+0x2bd/0x900 mm/slub.c:5662
kmalloc_noprof include/linux/slab.h:961 [inline]
indx_read+0x41d/0xad0 fs/ntfs3/index.c:1059
indx_find+0x447/0x900 fs/ntfs3/index.c:1179
dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254
ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85
__lookup_slow+0x241/0x450 fs/namei.c:1816
lookup_slow fs/namei.c:1833 [inline]
walk_component+0x31c/0x570 fs/namei.c:2151
link_path_walk+0x592/0xd60 fs/namei.c:2519
path_lookupat+0x138/0x660 fs/namei.c:2675
filename_lookup+0x1f3/0x560 fs/namei.c:2705
filename_setxattr+0xad/0x1c0 fs/xattr.c:660
path_setxattrat+0x1d8/0x280 fs/xattr.c:713
__do_sys_lsetxattr fs/xattr.c:754 [inline]
__se_sys_lsetxattr fs/xattr.c:750 [inline]
__x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750
...
[CAUSE]
The index-header validators only validated INDEX_HDR-level geometry.
They did not walk each NTFS_DE to verify entry alignment, subnode
layout, or that key_size fit inside the entry payload. They also
allowed a last sentinel entry to carry a non-zero key_size.
[FIX]
Walk every NTFS_DE in ntfs3's index-header validators and reject
entries with invalid layout, mismatched subnode state, oversized
key_size, or non-zero sentinel keys before lookup or log replay can
consume them.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 24 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: validate index entry key bounds [BUG] A malformed NTFS directory index entry can advertise a key_size larger than the bytes actually present in its NTFS_DE payload. Directory lookup then passes that malformed key to cmp_fnames(), which can read past the end of the kmalloc'ed index buffer. BUG: KASAN: slab-out-of-bounds in fname_full_size fs/ntfs3/ntfs.h:590 [inline] BUG: KASAN: slab-out-of-bounds in cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46 Read of size 1 at addr ffff88801c313018 by task syz.6.3365/9279 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xd1/0x650 mm/kasan/report.c:482 kasan_report+0xfb/0x140 mm/kasan/report.c:595 __asan_report_load1_noabort+0x14/0x30 mm/kasan/report_generic.c:378 fname_full_size fs/ntfs3/ntfs.h:590 [inline] cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46 hdr_find_e.isra.0+0x3ed/0x670 fs/ntfs3/index.c:762 indx_find+0x4b5/0x900 fs/ntfs3/index.c:1186 dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254 ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85 __lookup_slow+0x241/0x450 fs/namei.c:1816 lookup_slow fs/namei.c:1833 [inline] walk_component+0x31c/0x570 fs/namei.c:2151 link_path_walk+0x592/0xd60 fs/namei.c:2519 path_lookupat+0x138/0x660 fs/namei.c:2675 filename_lookup+0x1f3/0x560 fs/namei.c:2705 filename_setxattr+0xad/0x1c0 fs/xattr.c:660 path_setxattrat+0x1d8/0x280 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750 ... Allocated by task 9279: kasan_save_stack+0x39/0x70 mm/kasan/common.c:56 kasan_save_track+0x14/0x40 mm/kasan/common.c:77 kasan_save_alloc_info+0x37/0x60 mm/kasan/generic.c:573 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xc3/0xd0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5650 [inline] __kmalloc_noprof+0x2bd/0x900 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] indx_read+0x41d/0xad0 fs/ntfs3/index.c:1059 indx_find+0x447/0x900 fs/ntfs3/index.c:1179 dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254 ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85 __lookup_slow+0x241/0x450 fs/namei.c:1816 lookup_slow fs/namei.c:1833 [inline] walk_component+0x31c/0x570 fs/namei.c:2151 link_path_walk+0x592/0xd60 fs/namei.c:2519 path_lookupat+0x138/0x660 fs/namei.c:2675 filename_lookup+0x1f3/0x560 fs/namei.c:2705 filename_setxattr+0xad/0x1c0 fs/xattr.c:660 path_setxattrat+0x1d8/0x280 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750 ... [CAUSE] The index-header validators only validated INDEX_HDR-level geometry. They did not walk each NTFS_DE to verify entry alignment, subnode layout, or that key_size fit inside the entry payload. They also allowed a last sentinel entry to carry a non-zero key_size. [FIX] Walk every NTFS_DE in ntfs3's index-header validators and reject entries with invalid layout, mismatched subnode state, oversized key_size, or non-zero sentinel keys before lookup or log replay can consume them. | |
| Title | fs/ntfs3: validate index entry key bounds | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-24T16:03:51.466Z
Reserved: 2026-09-24T14:53:16.869Z
Link: CVE-2026-97438
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-24T17:17:21.930
Modified: 2026-09-24T17:17:21.930
Link: CVE-2026-97438
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.