[for-next][PATCH 02/12] user_events: Fix potential uninitialized pointer while parsing field

[Steven Rostedt]

From: Beau Belgrave <beaub@xxxxxxxxxxxxxxxxxxx>

Ensure name is initialized by default to NULL to prevent possible edge
cases that could lead to it being left uninitialized. Add an explicit
check for NULL name to ensure edge boundaries.

Link: https://lore.kernel.org/bpf/20220224105334.GA2248@kili/
Link: https://lore.kernel.org/linux-trace-devel/20220224181637.2129-1-beaub@xxxxxxxxxxxxxxxxxxx

Signed-off-by: Beau Belgrave <beaub@xxxxxxxxxxxxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
 kernel/trace/trace_events_user.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 2b5e9fdb63a0..9a6191a6a786 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -362,6 +362,8 @@ static int user_event_parse_field(char *field, struct user_event *user,
 	*field++ = '\0';
 	depth++;
 parse:
+	name = NULL;
+
 	while ((part = strsep(&field, " ")) != NULL) {
 		switch (depth++) {
 		case FIELD_DEPTH_TYPE:
@@ -382,7 +384,7 @@ static int user_event_parse_field(char *field, struct user_event *user,
 		}
 	}
 
-	if (depth < FIELD_DEPTH_SIZE)
+	if (depth < FIELD_DEPTH_SIZE || !name)
 		return -EINVAL;
 
 	if (depth == FIELD_DEPTH_SIZE)
-- 
2.35.1