selftests/sgx: Fix uninitialized pointer dereference in error path

[ Upstream commit 79eba8c924f7decfa71ddf187d38cb9f5f2cd7b3 ]

Ensure ctx is zero-initialized, such that the encl_measure function will
not call EVP_MD_CTX_destroy with an uninitialized ctx pointer in case of an
early error during key generation.

Fixes: 2adcba79e69d ("selftests/x86: Add a selftest for SGX")
Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/all/20231005153854.25566-2-jo.vanbulck%40cs.kuleuven.be
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c
index a07896a..d73b29b 100644 (file)
--- a/tools/testing/selftests/sgx/sigstruct.c
+++ b/tools/testing/selftests/sgx/sigstruct.c
@@ -318,9 +318,9 @@ bool encl_measure(struct encl *encl)
        struct sgx_sigstruct *sigstruct = &encl->sigstruct;
        struct sgx_sigstruct_payload payload;
        uint8_t digest[SHA256_DIGEST_LENGTH];
+       EVP_MD_CTX *ctx = NULL;
        unsigned int siglen;
        RSA *key = NULL;
-       EVP_MD_CTX *ctx;
        int i;
 
        memset(sigstruct, 0, sizeof(*sigstruct));
@@ -384,7 +384,8 @@ bool encl_measure(struct encl *encl)
        return true;
 
 err:
-       EVP_MD_CTX_destroy(ctx);
+       if (ctx)
+               EVP_MD_CTX_destroy(ctx);
        RSA_free(key);
        return false;
 }