From: lei lu llfamsec@gmail.com
[ Upstream commit 556bdf27c2dd5c74a9caacbe524b943a6cd42d99 ]
Added bounds checking to make sure that every attr don't stray beyond valid memory region.
Signed-off-by: lei lu llfamsec@gmail.com Signed-off-by: Konstantin Komarov almaz.alexandrovich@paragon-software.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ntfs3/record.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-)
diff --git a/fs/ntfs3/record.c b/fs/ntfs3/record.c index 6c76503edc200..2a375247b3c09 100644 --- a/fs/ntfs3/record.c +++ b/fs/ntfs3/record.c @@ -223,28 +223,19 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr) prev_type = 0; attr = Add2Ptr(rec, off); } else { - /* Check if input attr inside record. */ + /* + * We don't need to check previous attr here. There is + * a bounds checking in the previous round. + */ off = PtrOffset(rec, attr); - if (off >= used) - return NULL;
asize = le32_to_cpu(attr->size); - if (asize < SIZEOF_RESIDENT) { - /* Impossible 'cause we should not return such attribute. */ - return NULL; - } - - /* Overflow check. */ - if (off + asize < off) - return NULL;
prev_type = le32_to_cpu(attr->type); attr = Add2Ptr(attr, asize); off += asize; }
- asize = le32_to_cpu(attr->size); - /* Can we use the first field (attr->type). */ if (off + 8 > used) { static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8); @@ -265,6 +256,12 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr) if (t32 < prev_type) 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) return NULL;