From 090f612756a9720ec18b0b130e28be49839d7cb5 Mon Sep 17 00:00:00 2001 From: Konstantin Komarov Date: Thu, 5 Sep 2024 15:03:48 +0300 Subject: [PATCH] fs/ntfs3: Sequential field availability check in mi_enum_attr() 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 --- 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;