From: Namjae Jeon linkinjeon@kernel.org

commit d6e13e19063db24f94b690159d0633aaf72a0f03 upstream.

If osidoffset, gsidoffset and dacloffset could be greater than smb_ntsd struct size. If it is smaller, It could cause slab-out-of-bounds. And when validating sid, It need to check it included subauth array size.

Cc: stable@vger.kernel.org Reported-by: Norbert Szetei norbert@doyensec.com Tested-by: Norbert Szetei norbert@doyensec.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Rajani Kantha 681739313@139.com --- fs/smb/server/smbacl.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)

diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c index 90c5e3edbf46..5c05f0e8b6ea 100644 --- a/fs/smb/server/smbacl.c +++ b/fs/smb/server/smbacl.c @@ -815,6 +815,13 @@ static int parse_sid(struct smb_sid *psid, char *end_of_acl) return -EINVAL; }

+ if (!psid->num_subauth) + return 0; + + if (psid->num_subauth > SID_MAX_SUB_AUTHORITIES || + end_of_acl < (char *)psid + 8 + sizeof(__le32) * psid->num_subauth) + return -EINVAL; + return 0; }

@@ -856,6 +863,9 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, pntsd->type = cpu_to_le16(DACL_PRESENT);

if (pntsd->osidoffset) { + if (le32_to_cpu(pntsd->osidoffset) < sizeof(struct smb_ntsd)) + return -EINVAL; + rc = parse_sid(owner_sid_ptr, end_of_acl); if (rc) { pr_err("%s: Error %d parsing Owner SID\n", __func__, rc); @@ -871,6 +881,9 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, }

if (pntsd->gsidoffset) { + if (le32_to_cpu(pntsd->gsidoffset) < sizeof(struct smb_ntsd)) + return -EINVAL; + rc = parse_sid(group_sid_ptr, end_of_acl); if (rc) { pr_err("%s: Error %d mapping Owner SID to gid\n", @@ -892,6 +905,9 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, pntsd->type |= cpu_to_le16(DACL_PROTECTED);

if (dacloffset) { + if (dacloffset < sizeof(struct smb_ntsd)) + return -EINVAL; + parse_dacl(user_ns, dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr, fattr); }