fscache_cookie_enabled: check cookie is valid before accessing it

fscache_cookie_enabled() could be called on NULL cookies and cause a null pointer dereference when accessing cookie flags: just make sure the cookie is valid first Suggested-by: David Howells <[email protected]> Acked-by: David Howells <[email protected]> Signed-off-by: Dominique Martinet <[email protected]>
3xh4u573d · Nov 3, 2021 · 0dc54bd · 0dc54bd
1 parent 4cd82a5
commit 0dc54bd
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
@@ -167,7 +167,7 @@ struct fscache_cookie {
 
 static inline bool fscache_cookie_enabled(struct fscache_cookie *cookie)
 {
-	return test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
+	return fscache_cookie_valid(cookie) && test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
 }
 
 /*