From 8f77150c15f87796570125a43509f9a81a3d9e49 Mon Sep 17 00:00:00 2001 From: Hyunchul Lee Date: Fri, 24 Sep 2021 22:22:22 +0900 Subject: ksmbd: add buffer validation for SMB2_CREATE_CONTEXT Add buffer validation for SMB2_CREATE_CONTEXT. Cc: Ronnie Sahlberg Reviewed-by: Ralph Boehme Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/ksmbd/smbacl.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'fs/ksmbd/smbacl.c') diff --git a/fs/ksmbd/smbacl.c b/fs/ksmbd/smbacl.c index 0a95cdec8c80..bd792db32623 100644 --- a/fs/ksmbd/smbacl.c +++ b/fs/ksmbd/smbacl.c @@ -380,7 +380,7 @@ static void parse_dacl(struct user_namespace *user_ns, { int i, ret; int num_aces = 0; - int acl_size; + unsigned int acl_size; char *acl_base; struct smb_ace **ppace; struct posix_acl_entry *cf_pace, *cf_pdace; @@ -392,7 +392,7 @@ static void parse_dacl(struct user_namespace *user_ns, return; /* validate that we do not go past end of acl */ - if (end_of_acl <= (char *)pdacl || + if (end_of_acl < (char *)pdacl + sizeof(struct smb_acl) || end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) { pr_err("ACL too small to parse DACL\n"); return; @@ -431,8 +431,22 @@ static void parse_dacl(struct user_namespace *user_ns, * user/group/other have no permissions */ for (i = 0; i < num_aces; ++i) { + if (end_of_acl - acl_base < acl_size) + break; + ppace[i] = (struct smb_ace *)(acl_base + acl_size); acl_base = (char *)ppace[i]; + acl_size = offsetof(struct smb_ace, sid) + + offsetof(struct smb_sid, sub_auth); + + if (end_of_acl - acl_base < acl_size || + ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES || + (end_of_acl - acl_base < + acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) || + (le16_to_cpu(ppace[i]->size) < + acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth)) + break; + acl_size = le16_to_cpu(ppace[i]->size); ppace[i]->access_req = smb_map_generic_desired_access(ppace[i]->access_req); @@ -807,6 +821,9 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, if (!pntsd) return -EIO; + if (acl_len < sizeof(struct smb_ntsd)) + return -EINVAL; + owner_sid_ptr = (struct smb_sid *)((char *)pntsd + le32_to_cpu(pntsd->osidoffset)); group_sid_ptr = (struct smb_sid *)((char *)pntsd + -- cgit v1.2.3