Error handling fixes, may contain 4.2 material

[PATCH 04/21] crypto: Fix certificate file error handling crash bug

Posted by Markus Armbruster 6 years, 2 months ago

qcrypto_tls_creds_load_cert() passes uninitialized GError *gerr by
reference to g_file_get_contents().  When g_file_get_contents() fails,
it'll try to set a GError.  Unless @gerr is null by dumb luck, this
logs a ERROR_OVERWRITTEN_WARNING warning message and leaves @gerr
unchanged.  qcrypto_tls_creds_load_cert() then dereferences the
uninitialized @gerr.

Fix by initializing @gerr properly.

Fixes: 9a2fd4347c40321f5cbb4ab4220e759fcbf87d03
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 crypto/tlscredsx509.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/tlscredsx509.c b/crypto/tlscredsx509.c
index 01fc304e5d..53a4368f49 100644
--- a/crypto/tlscredsx509.c
+++ b/crypto/tlscredsx509.c
@@ -380,7 +380,7 @@ qcrypto_tls_creds_load_cert(QCryptoTLSCredsX509 *creds,
     gnutls_x509_crt_t cert = NULL;
     g_autofree char *buf = NULL;
     gsize buflen;
-    GError *gerr;
+    GError *gerr = NULL;
     int ret = -1;
     int err;
 
-- 
2.21.0

Re: [PATCH 04/21] crypto: Fix certificate file error handling crash bug

Posted by Vladimir Sementsov-Ogievskiy 6 years, 2 months ago

30.11.2019 22:42, Markus Armbruster wrote:
> qcrypto_tls_creds_load_cert() passes uninitialized GError *gerr by
> reference to g_file_get_contents().  When g_file_get_contents() fails,
> it'll try to set a GError.  Unless @gerr is null by dumb luck, this
> logs a ERROR_OVERWRITTEN_WARNING warning message and leaves @gerr
> unchanged.  qcrypto_tls_creds_load_cert() then dereferences the
> uninitialized @gerr.
> 
> Fix by initializing @gerr properly.
> 
> Fixes: 9a2fd4347c40321f5cbb4ab4220e759fcbf87d03
> Cc: "Daniel P. Berrangé" <berrange@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>   crypto/tlscredsx509.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/crypto/tlscredsx509.c b/crypto/tlscredsx509.c
> index 01fc304e5d..53a4368f49 100644
> --- a/crypto/tlscredsx509.c
> +++ b/crypto/tlscredsx509.c
> @@ -380,7 +380,7 @@ qcrypto_tls_creds_load_cert(QCryptoTLSCredsX509 *creds,
>       gnutls_x509_crt_t cert = NULL;
>       g_autofree char *buf = NULL;
>       gsize buflen;
> -    GError *gerr;
> +    GError *gerr = NULL;
>       int ret = -1;
>       int err;
>   
> 

I didn't check the logic in commit message (and I don't know how GError works),
but initializing local pointer to NULL never hurts:

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

-- 
Best regards,
Vladimir