Re: [PATCH] libselinux: Cached security context not accurate

[Johannes Segitz <jsegitz@xxxxxxx>]

On Fri, Jan 21, 2022 at 01:06:16PM +0100, Christian Göttsche wrote:
> Wouldn't it make logically more sense to first check if pid is zero
> and then check if the cache is set, cause we never want to access the
> cache if not operating on out own process?

Yes, I changed that

> Also isn't setprocattrcon_raw() affected too?

Of course. I managed to attach the wrong file that only had the change for
getprocattrcon_raw. Attached is the full patch

Johannes
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Index: libselinux-3.3/src/procattr.c
===================================================================
--- libselinux-3.3.orig/src/procattr.c
+++ libselinux-3.3/src/procattr.c
@@ -148,7 +148,7 @@ static int getprocattrcon_raw(char ** co
 			return -1;
 	}
 
-	if (prev_context && prev_context != UNSET) {
+	if (pid == 0 && prev_context && prev_context != UNSET) {
 		*context = strdup(prev_context);
 		if (!(*context)) {
 			return -1;
@@ -242,9 +242,9 @@ static int setprocattrcon_raw(const char
 			return -1;
 	}
 
-	if (!context && !*prev_context)
+	if (pid == 0 && !context && !*prev_context)
 		return 0;
-	if (context && *prev_context && *prev_context != UNSET
+	if (pid == 0 && context && *prev_context && *prev_context != UNSET
 	    && !strcmp(context, *prev_context))
 		return 0;
 
@@ -272,9 +272,11 @@ out:
 		free(context2);
 		return -1;
 	} else {
-		if (*prev_context != UNSET)
-			free(*prev_context);
-		*prev_context = context2;
+		if (pid == 0) {
+			if (*prev_context != UNSET)
+				free(*prev_context);
+			*prev_context = context2;
+		}
 		return 0;
 	}
 }

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