From 55a81a3189d42385a6cfcd65bdafe833123928a7 Mon Sep 17 00:00:00 2001
From: Miroslav Cimerman <mc@doas.su>
Date: Tue, 22 Apr 2025 12:07:30 +0200
Subject: [PATCH] uspace/app/blkdump: fix argv null deref

---
 uspace/app/blkdump/blkdump.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/uspace/app/blkdump/blkdump.c b/uspace/app/blkdump/blkdump.c
index 170dbfd1d2..beafdee2c8 100644
--- a/uspace/app/blkdump/blkdump.c
+++ b/uspace/app/blkdump/blkdump.c
@@ -94,7 +94,7 @@ int main(int argc, char **argv)
 		relative = true;
 	}
 
-	if (str_cmp(*argv, "--offset") == 0) {
+	if (*argv && str_cmp(*argv, "--offset") == 0) {
 		--argc;
 		++argv;
 		if (*argv == NULL) {
@@ -114,7 +114,7 @@ int main(int argc, char **argv)
 		++argv;
 	}
 
-	if (str_cmp(*argv, "--count") == 0) {
+	if (*argv && str_cmp(*argv, "--count") == 0) {
 		--argc;
 		++argv;
 		if (*argv == NULL) {
@@ -135,6 +135,12 @@ int main(int argc, char **argv)
 	}
 
 devname:
+	if (*argv == NULL) {
+		printf(NAME ": Error, argument missing (device_name).\n");
+		syntax_print();
+		return 1;
+	}
+
 	if (argc != 1) {
 		printf(NAME ": Error, unexpected argument.\n");
 		syntax_print();