From: Joseph Sutton <josephsutton@catalyst.net.nz>
Date: Mon, 13 Feb 2023 01:58:52 +0000 (+1300)
Subject: smbd/notify: Handle allocation failure
X-Git-Tag: talloc-2.4.1~941
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=78ca3e16da77ba13ef5fc0ae303bb4a371ebcf8d;p=thirdparty%2Fsamba.git

smbd/notify: Handle allocation failure

If a talloc function returns NULL, indicating failure, the failure could
be masked by the next talloc call allocating on the NULL context.

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andreas Schneider <asn@samba.org>
---

diff --git a/source3/smbd/notify.c b/source3/smbd/notify.c
index c18ad0027b6..87f08124171 100644
--- a/source3/smbd/notify.c
+++ b/source3/smbd/notify.c
@@ -864,33 +864,83 @@ char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32_t filter)
 	char *result = NULL;
 
 	result = talloc_strdup(mem_ctx, "");
+	if (result == NULL) {
+		return NULL;
+	}
 
-	if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
+	if (filter & FILE_NOTIFY_CHANGE_FILE_NAME) {
 		result = talloc_asprintf_append(result, "FILE_NAME|");
-	if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_DIR_NAME) {
 		result = talloc_asprintf_append(result, "DIR_NAME|");
-	if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES) {
 		result = talloc_asprintf_append(result, "ATTRIBUTES|");
-	if (filter & FILE_NOTIFY_CHANGE_SIZE)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_SIZE) {
 		result = talloc_asprintf_append(result, "SIZE|");
-	if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE) {
 		result = talloc_asprintf_append(result, "LAST_WRITE|");
-	if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS) {
 		result = talloc_asprintf_append(result, "LAST_ACCESS|");
-	if (filter & FILE_NOTIFY_CHANGE_CREATION)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_CREATION) {
 		result = talloc_asprintf_append(result, "CREATION|");
-	if (filter & FILE_NOTIFY_CHANGE_EA)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_EA) {
 		result = talloc_asprintf_append(result, "EA|");
-	if (filter & FILE_NOTIFY_CHANGE_SECURITY)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_SECURITY) {
 		result = talloc_asprintf_append(result, "SECURITY|");
-	if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME) {
 		result = talloc_asprintf_append(result, "STREAM_NAME|");
-	if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE) {
 		result = talloc_asprintf_append(result, "STREAM_SIZE|");
-	if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE)
+		if (result == NULL) {
+			return NULL;
+		}
+	}
+	if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE) {
 		result = talloc_asprintf_append(result, "STREAM_WRITE|");
+		if (result == NULL) {
+			return NULL;
+		}
+	}
 
-	if (result == NULL) return NULL;
 	if (*result == '\0') return result;
 
 	result[strlen(result)-1] = '\0';