From: Gerhard Sittig <redacted>
Date: Wed, 31 Aug 2022 15:37:05 +0000 (-0600)
Subject: asix-sigma: check sdi before dereferencing a NULL pointer
X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=commitdiff_plain;h=05a8a5f3c34fab5fbabe241dacd929616ebae88f

asix-sigma: check sdi before dereferencing a NULL pointer

The asix-sigma config_list() routine unconditionally dereferenced the
'sdi' pointer, which could be NULL. Properly check before dereferencing.
This issue was introduced in commit eabf9ca630f4. How to reproduce:

  $ sigrok-cli -d asix-sigma --show

Reported-By: Paul Kasemir <redacted>
---

diff --git a/src/hardware/asix-sigma/api.c b/src/hardware/asix-sigma/api.c
index 72da2c14..f1b96bb7 100644
--- a/src/hardware/asix-sigma/api.c
+++ b/src/hardware/asix-sigma/api.c
@@ -401,7 +401,7 @@ static int config_list(uint32_t key, GVariant **data,
 	const char **names;
 	size_t count;
 
-	devc = sdi->priv;
+	devc = sdi ? sdi->priv : NULL;
 	switch (key) {
 	case SR_CONF_SCAN_OPTIONS:
 	case SR_CONF_DEVICE_OPTIONS:
@@ -413,6 +413,8 @@ static int config_list(uint32_t key, GVariant **data,
 		*data = sigma_get_samplerates_list();
 		break;
 	case SR_CONF_EXTERNAL_CLOCK_SOURCE:
+		if (!devc)
+			return SR_ERR_ARG;
 		names = (const char **)devc->channel_names;
 		count = g_strv_length(devc->channel_names);
 		*data = g_variant_new_strv(names, count);