From 638a5007a5d240d6fa901aa822cfeef94fe36e85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Veronika=20Hanul=C3=ADkov=C3=A1?= <vhanulik@redhat.com>
Date: Thu, 10 Aug 2023 12:20:33 +0200
Subject: [PATCH] pkcs15-pubkey.c: Avoid double-free

Thanks OSS-Fuzz
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=60616
---
 src/libopensc/pkcs15-pubkey.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/libopensc/pkcs15-pubkey.c b/src/libopensc/pkcs15-pubkey.c
index 7107c47cbc..49b514968b 100644
--- a/src/libopensc/pkcs15-pubkey.c
+++ b/src/libopensc/pkcs15-pubkey.c
@@ -351,8 +351,12 @@ int sc_pkcs15_decode_pukdf_entry(struct sc_pkcs15_card *p15card,
 err:
 	if (r < 0) {
 		sc_pkcs15_free_pubkey_info(info);
-		if (der->len)
+		if (der->len) {
 			free(der->value);
+			/* der points to obj->content */
+			obj->content.value = NULL;
+			obj->content.len = 0;
+		}
 	}
 
 	LOG_FUNC_RETURN(ctx, r);