Fix a crash in intercept mode running a command with NULL argv[0].

millert · millert · commit 24cc3f4c912f · 2023-07-12T09:29:00.000-06:00
Newer Linux kernels replace a NULL argv[0] with the empty string,
we should as well.

--HG--
branch : 1.9
diff --git a/src/exec_ptrace.c b/src/exec_ptrace.c
@@ -1795,7 +1795,7 @@ ptrace_intercept_execve(pid_t pid, struct intercept_closure *closure)
     }
 
     /* We can only pass the pathname to exececute via argv[0] (plugin API). */
-    orig_argv0 = argv[0];
+    orig_argv0 = argv[0] ? argv[0] : (char *)"";
     argv[0] = pathname;
     if (argc == 0) {
 	/* Rewrite an empty argv[] with the path to execute. */

Original file line number	Diff line number	Diff line change
`@@ -1795,7 +1795,7 @@ ptrace_intercept_execve(pid_t pid, struct intercept_closure *closure)`
`1795`	`1795`	`}`
`1796`	`1796`
`1797`	`1797`	`/* We can only pass the pathname to exececute via argv[0] (plugin API). */`
`1798`		`- orig_argv0 = argv[0];`
	`1798`	`+ orig_argv0 = argv[0] ? argv[0] : (char *)"";`
`1799`	`1799`	`argv[0] = pathname;`
`1800`	`1800`	`if (argc == 0) {`
`1801`	`1801`	`/* Rewrite an empty argv[] with the path to execute. */`