Fix segfault of pv command. (#4883)

A non-numerical argument set repeat to 0 and
lead to an integer overflow further down.
This lead to OOB reading of memory.

Author: Rot127

librz/core/cmd/cmd_print.c

@@ -4234,7 +4234,7 @@ static bool print_value(RzCore *core, PrintValueOptions *opts, RzCmdStateOutput
 
 static RzCmdStatus print_value_size(RzCore *core, RzCmdStateOutput *state, int argc, const char **argv, ut64 size) {
 	int repeat = argc > 1 ? rz_num_math(NULL, argv[1]) : 1;
-	if (repeat < 0) {
+	if (repeat <= 0) {
 		return RZ_CMD_STATUS_ERROR;
 	}
 	PrintValueOptions opts = {

test/db/cmd/cmd_pv

@@ -0,0 +1,19 @@
+NAME=pv
+FILE=
+CMDS=<<EOF
+# Invalid input, check for segfault
+pv iihasidbib
+pv 0x9
+EOF
+EXPECT=<<EOF
+0x0000000000000000
+0x0000000000000000
+0x0000000000000000
+0x0000000000000000
+0x0000000000000000
+0x0000000000000000
+0x0000000000000000
+0x0000000000000000
+0x0000000000000000
+EOF
+RUN