[PATCH 4.19 166/205] crypto: user - fix leaking uninitialized memory to userspace

Greg Kroah-Hartman
2018-11-19T16:37:32Z

From: Eric Biggers <ebiggers@google.com>

commit f43f39958beb206b53292801e216d9b8a660f087 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
crypto/crypto_user.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -83,7 +83,7 @@ static int crypto_report_cipher(struct s
{
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;
@@ -102,7 +102,7 @@ static int crypto_report_comp(struct sk_
{
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;
@@ -116,7 +116,7 @@ static int crypto_report_acomp(struct sk
{
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))
@@ -131,7 +131,7 @@ static int crypto_report_akcipher(struct
{
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))
@@ -146,7 +146,7 @@ static int crypto_report_kpp(struct sk_b
{
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))
@@ -160,10 +160,10 @@ 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;
@@ -176,7 +176,7 @@ static int crypto_report_one(struct cryp
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;