session: ignore non-string username attribute upon restore

When restoring session information from blob data, only consider the
embedded username attribute if it is a string value.

Other types may cause invalid memory accesses when attempting to strcmp()
the attribute value.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 3 insertions, 0 deletions

diff --git a/session.c b/session.c
index 3bef025..3ed4519 100644
--- a/session.c
+++ b/session.c
@@ -1288,6 +1288,9 @@ rpc_session_from_blob(struct uci_context *uci, struct blob_attr *attr)
 	blobmsg_for_each_attr(data, tb[RPC_DUMP_DATA], rem) {
 		rpc_session_set(ses, data);
 
+		if (blobmsg_type(data) != BLOBMSG_TYPE_STRING)
+			continue;
+
 		if (!strcmp(blobmsg_name(data), "username"))
 			user = blobmsg_get_string(data);
 	}