diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
new file mode 100644
index 0000000..97daee1
--- /dev/null
+++ b/.github/workflows/codeql-analysis.yml
@@ -0,0 +1,70 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master ]
+  schedule:
+    - cron: '29 21 * * 1'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'cpp' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
+        # Learn more about CodeQL language support at https://git.io/codeql-language-support
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1
diff --git a/asc2log.c b/asc2log.c
index 7f932ef..ea6b486 100644
--- a/asc2log.c
+++ b/asc2log.c
@@ -50,6 +50,7 @@
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>
+#include <limits.h>
 
 #include <linux/can.h>
 #include <linux/can/error.h>
@@ -206,6 +207,13 @@ void eval_can(char* buf, struct timeval *date_tvp, char timestamps, char base, i
 		if (strlen(dir) != 2) /* "Rx" or "Tx" */
 			return;
 
+		/* check for signed integer overflow */
+		if (dplace == 4 && read_tv.tv_usec >= INT_MAX / 100)
+			return;
+
+		if (dplace == 5 && read_tv.tv_usec >= INT_MAX / 10)
+			return;
+
 		if (dir[0] == 'R')
 			extra_info = " R\n";
 		else
@@ -269,6 +277,14 @@ void eval_canfd(char* buf, struct timeval *date_tvp, char timestamps, int dplace
 	if (strlen(dir) != 2) /* "Rx" or "Tx" */
 		return;
 
+	/* check for signed integer overflow */
+	if (dplace == 4 && read_tv.tv_usec >= INT_MAX / 100)
+		return;
+
+	/* check for signed integer overflow */
+	if (dplace == 5 && read_tv.tv_usec >= INT_MAX / 10)
+		return;
+
 	if (dir[0] == 'R')
 		extra_info = " R\n";
 	else
diff --git a/lib.c b/lib.c
index 935270b..81fe64b 100644
--- a/lib.c
+++ b/lib.c
@@ -159,7 +159,7 @@ int parse_canframe(char *cs, struct canfd_frame *cf) {
 	int i, idx, dlen, len;
 	int maxdlen = CAN_MAX_DLEN;
 	int ret = CAN_MTU;
-	unsigned char tmp;
+	canid_t tmp;
 
 	len = strlen(cs);
 	//printf("'%s' len %d\n", cs, len);
@@ -568,10 +568,20 @@ static int snprintf_error_data(char *buf, size_t len, uint8_t err,
 
 	for (i = 0; i < arr_len; i++) {
 		if (err & (1 << i)) {
-			if (count)
-				n += snprintf(buf + n, len - n, ",");
-			n += snprintf(buf + n, len - n, "%s", arr[i]);
-			count++;
+			int tmp_n = 0;
+			if (count){
+				/* Fix for potential buffer overflow https://lgtm.com/rules/1505913226124/ */
+				tmp_n = snprintf(buf + n, len - n, ",");
+				if (tmp_n < 0 || tmp_n >= len - n){
+					return n;
+				}
+				n += tmp_n;
+			}
+			tmp_n = snprintf(buf + n, len - n, "%s", arr[i]);
+			if (tmp_n < 0 || tmp_n >= len - n){
+				return n;
+			}
+			n += tmp_n;
 		}
 	}
 
@@ -644,9 +654,20 @@ void snprintf_can_error_frame(char *buf, size_t len, const struct canfd_frame *c
 	for (i = 0; i < (int)ARRAY_SIZE(error_classes); i++) {
 		mask = 1 << i;
 		if (class & mask) {
-			if (classes)
-				n += snprintf(buf + n, len - n, "%s", sep);
-			n += snprintf(buf + n, len - n, "%s", error_classes[i]);
+			int tmp_n = 0;
+			if (classes){
+				/* Fix for potential buffer overflow https://lgtm.com/rules/1505913226124/ */
+				tmp_n = snprintf(buf + n, len - n, "%s", sep);
+				if (tmp_n < 0 || tmp_n >= len - n){
+					return;
+				}
+				n += tmp_n;
+			}
+			tmp_n = snprintf(buf + n, len - n, "%s", error_classes[i]);
+			if (tmp_n < 0 || tmp_n >= len - n){
+				return;
+			}
+			n += tmp_n;
 			if (mask == CAN_ERR_LOSTARB)
 				n += snprintf_error_lostarb(buf + n, len - n,
 							   cf);