commit a746c35822e557766d1871ec976490a71e6962d9
Author: Zhi Li <yieli@redhat.com>
Date:   Wed Apr 5 12:08:10 2023 -0400

    rpcdebug: avoid buffer underflow if read() returns 0
    
    Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2176740
    
    Signed-off-by: Zhi Li <yieli@redhat.com>
    Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/tools/rpcdebug/rpcdebug.c b/tools/rpcdebug/rpcdebug.c
index 68206cc5..ec05179e 100644
--- a/tools/rpcdebug/rpcdebug.c
+++ b/tools/rpcdebug/rpcdebug.c
@@ -257,7 +257,7 @@ get_flags(char *module)
 		perror(filename);
 		exit(1);
 	}
-	if ((len = read(sysfd, buffer, sizeof(buffer))) < 0) {
+	if ((len = read(sysfd, buffer, sizeof(buffer))) <= 0) {
 		perror("read");
 		exit(1);
 	}