crypto: user - fix leaking uninitialized memory to userspace

All bytes of the NETLINK_CRYPTO report structures must be initialized,
since they are copied to userspace.  The change from strncpy() to
strlcpy() broke this.  As a minimal fix, change it back.

Fixes: 4473710df1f8 ("crypto: user - Prepare for CRYPTO_MAX_ALG_NAME expansion")
Cc: <stable@vger.kernel.org> # v4.12+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/crypto_user_base.c b/crypto/crypto_user_base.c
index e41f6cc33fff49f2b35ad52504742ba79c70c3b8..784748dbb19f0c58482ad18c761c7de121d41928 100644 (file)
--- a/crypto/crypto_user_base.c
+++ b/crypto/crypto_user_base.c
@@ -84,7 +84,7 @@ static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
 {
        struct crypto_report_cipher rcipher;
 
-       strlcpy(rcipher.type, "cipher", sizeof(rcipher.type));
+       strncpy(rcipher.type, "cipher", sizeof(rcipher.type));
 
        rcipher.blocksize = alg->cra_blocksize;
        rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
@@ -103,7 +103,7 @@ static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
 {
        struct crypto_report_comp rcomp;
 
-       strlcpy(rcomp.type, "compression", sizeof(rcomp.type));
+       strncpy(rcomp.type, "compression", sizeof(rcomp.type));
        if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
                    sizeof(struct crypto_report_comp), &rcomp))
                goto nla_put_failure;
@@ -117,7 +117,7 @@ static int crypto_report_acomp(struct sk_buff *skb, struct crypto_alg *alg)
 {
        struct crypto_report_acomp racomp;
 
-       strlcpy(racomp.type, "acomp", sizeof(racomp.type));
+       strncpy(racomp.type, "acomp", sizeof(racomp.type));
 
        if (nla_put(skb, CRYPTOCFGA_REPORT_ACOMP,
                    sizeof(struct crypto_report_acomp), &racomp))
@@ -132,7 +132,7 @@ static int crypto_report_akcipher(struct sk_buff *skb, struct crypto_alg *alg)
 {
        struct crypto_report_akcipher rakcipher;
 
-       strlcpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
+       strncpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
 
        if (nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER,
                    sizeof(struct crypto_report_akcipher), &rakcipher))
@@ -147,7 +147,7 @@ static int crypto_report_kpp(struct sk_buff *skb, struct crypto_alg *alg)
 {
        struct crypto_report_kpp rkpp;
 
-       strlcpy(rkpp.type, "kpp", sizeof(rkpp.type));
+       strncpy(rkpp.type, "kpp", sizeof(rkpp.type));
 
        if (nla_put(skb, CRYPTOCFGA_REPORT_KPP,
                    sizeof(struct crypto_report_kpp), &rkpp))
@@ -161,10 +161,10 @@ nla_put_failure:
 static int crypto_report_one(struct crypto_alg *alg,
                             struct crypto_user_alg *ualg, struct sk_buff *skb)
 {
-       strlcpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
-       strlcpy(ualg->cru_driver_name, alg->cra_driver_name,
+       strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
+       strncpy(ualg->cru_driver_name, alg->cra_driver_name,
                sizeof(ualg->cru_driver_name));
-       strlcpy(ualg->cru_module_name, module_name(alg->cra_module),
+       strncpy(ualg->cru_module_name, module_name(alg->cra_module),
                sizeof(ualg->cru_module_name));
 
        ualg->cru_type = 0;
@@ -177,7 +177,7 @@ static int crypto_report_one(struct crypto_alg *alg,
        if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
                struct crypto_report_larval rl;
 
-               strlcpy(rl.type, "larval", sizeof(rl.type));
+               strncpy(rl.type, "larval", sizeof(rl.type));
                if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL,
                            sizeof(struct crypto_report_larval), &rl))
                        goto nla_put_failure;