Merge tag 'v4.14.73' into linux-linaro-lsk-v4.14lsk-v4.14-18.09

This is the 4.14.73 stable release

# gpg: Signature made Sat 29 Sep 2018 11:06:11 BST
# gpg:                using RSA key 647F28654894E3BD457199BE38DBBDC86092693E
# gpg: Good signature from "Greg Kroah-Hartman <gregkh@linuxfoundation.org>" [unknown]
# gpg:                 aka "Greg Kroah-Hartman (Linux kernel stable release signing key) <greg@kroah.com>" [unknown]
# gpg:                 aka "Greg Kroah-Hartman <gregkh@kernel.org>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 647F 2865 4894 E3BD 4571  99BE 38DB BDC8 6092 693E

2 files changed, 24 insertions, 12 deletions

diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index a27fc8791551..ef24b4527459 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -376,8 +376,15 @@ static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 
 		new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 				pfData->FileNameLength;
-	} else
-		new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
+	} else {
+		u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
+
+		if (old_entry + next_offset < old_entry) {
+			cifs_dbg(VFS, "invalid offset %u\n", next_offset);
+			return NULL;
+		}
+		new_entry = old_entry + next_offset;
+	}
 	cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
 	/* validate that new_entry is not past end of SMB */
 	if (new_entry >= end_of_smb) {
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 078ec705a5cc..69309538ffb8 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2939,33 +2939,38 @@ num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size)
 	int len;
 	unsigned int entrycount = 0;
 	unsigned int next_offset = 0;
-	FILE_DIRECTORY_INFO *entryptr;
+	char *entryptr;
+	FILE_DIRECTORY_INFO *dir_info;
 
 	if (bufstart == NULL)
 		return 0;
 
-	entryptr = (FILE_DIRECTORY_INFO *)bufstart;
+	entryptr = bufstart;
 
 	while (1) {
-		entryptr = (FILE_DIRECTORY_INFO *)
-					((char *)entryptr + next_offset);
-
-		if ((char *)entryptr + size > end_of_buf) {
+		if (entryptr + next_offset < entryptr ||
+		    entryptr + next_offset > end_of_buf ||
+		    entryptr + next_offset + size > end_of_buf) {
 			cifs_dbg(VFS, "malformed search entry would overflow\n");
 			break;
 		}
 
-		len = le32_to_cpu(entryptr->FileNameLength);
-		if ((char *)entryptr + len + size > end_of_buf) {
+		entryptr = entryptr + next_offset;
+		dir_info = (FILE_DIRECTORY_INFO *)entryptr;
+
+		len = le32_to_cpu(dir_info->FileNameLength);
+		if (entryptr + len < entryptr ||
+		    entryptr + len > end_of_buf ||
+		    entryptr + len + size > end_of_buf) {
 			cifs_dbg(VFS, "directory entry name would overflow frame end of buf %p\n",
 				 end_of_buf);
 			break;
 		}
 
-		*lastentry = (char *)entryptr;
+		*lastentry = entryptr;
 		entrycount++;
 
-		next_offset = le32_to_cpu(entryptr->NextEntryOffset);
+		next_offset = le32_to_cpu(dir_info->NextEntryOffset);
 		if (!next_offset)
 			break;
 	}