The code is slightly reformatted to consistently check field availability
without duplication.
Fixes: 556bdf27c2dd ("ntfs3: Add bounds checking to mi_enum_attr()")
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
---
fs/ntfs3/record.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/fs/ntfs3/record.c b/fs/ntfs3/record.c
index 427c71be0f08..f810f0419d25 100644
--- a/fs/ntfs3/record.c
+++ b/fs/ntfs3/record.c
@@ -237,6 +237,7 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
}
/* Can we use the first field (attr->type). */
+ /* NOTE: this code also checks attr->size availability. */
if (off + 8 > used) {
static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
return NULL;
@@ -257,10 +258,6 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
return NULL;
asize = le32_to_cpu(attr->size);
- if (asize < SIZEOF_RESIDENT) {
- /* Impossible 'cause we should not return such attribute. */
- return NULL;
- }
/* Check overflow and boundary. */
if (off + asize < off || off + asize > used)
@@ -290,6 +287,10 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
if (attr->non_res != 1)
return NULL;
+ /* Can we use memory including attr->nres.valid_size? */
+ if (asize < SIZEOF_NONRESIDENT)
+ return NULL;
+
t16 = le16_to_cpu(attr->nres.run_off);
if (t16 > asize)
return NULL;
@@ -316,7 +317,8 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
if (!attr->nres.svcn && is_attr_ext(attr)) {
/* First segment of sparse/compressed attribute */
- if (asize + 8 < SIZEOF_NONRESIDENT_EX)
+ /* Can we use memory including attr->nres.total_size? */
+ if (asize < SIZEOF_NONRESIDENT_EX)
return NULL;
tot_size = le64_to_cpu(attr->nres.total_size);
@@ -326,9 +328,6 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
if (tot_size > alloc_size)
return NULL;
} else {
- if (asize + 8 < SIZEOF_NONRESIDENT)
- return NULL;
-
if (attr->nres.c_unit)
return NULL;
--
2.34.1
