xfrm: xfrm_user: use strscpy() for alg_name

Replace the strcpy() calls that copy the canonical algorithm name into
alg_name with strscpy() to avoid potential overflows and guarantee NULL
termination.

Destination is alg_name in xfrm_algo/xfrm_algo_auth/xfrm_algo_aead
(size CRYPTO_MAX_ALG_NAME).

Tested in QEMU (BusyBox/Alpine rootfs):
 - Added ESP AEAD (rfc4106(gcm(aes))) and classic ESP (sha256 + cbc(aes))
 - Verified canonical names via ip -d xfrm state
 - Checked IPComp negative (unknown algo) and deflate path

Signed-off-by: Miguel García <miguelgarciaroman8@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 684239018bec490c120c76fd6c41100bbb69a18a..010c9e6638c0cdbf0756af3fbfcb3b53f6bd88c6 100644 (file)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -593,7 +593,7 @@ static int attach_one_algo(struct xfrm_algo **algpp, u8 *props,
        if (!p)
                return -ENOMEM;
 
-       strcpy(p->alg_name, algo->name);
+       strscpy(p->alg_name, algo->name);
        *algpp = p;
        return 0;
 }
@@ -620,7 +620,7 @@ static int attach_crypt(struct xfrm_state *x, struct nlattr *rta,
        if (!p)
                return -ENOMEM;
 
-       strcpy(p->alg_name, algo->name);
+       strscpy(p->alg_name, algo->name);
        x->ealg = p;
        x->geniv = algo->uinfo.encr.geniv;
        return 0;
@@ -649,7 +649,7 @@ static int attach_auth(struct xfrm_algo_auth **algpp, u8 *props,
        if (!p)
                return -ENOMEM;
 
-       strcpy(p->alg_name, algo->name);
+       strscpy(p->alg_name, algo->name);
        p->alg_key_len = ualg->alg_key_len;
        p->alg_trunc_len = algo->uinfo.auth.icv_truncbits;
        memcpy(p->alg_key, ualg->alg_key, (ualg->alg_key_len + 7) / 8);
@@ -684,7 +684,7 @@ static int attach_auth_trunc(struct xfrm_algo_auth **algpp, u8 *props,
        if (!p)
                return -ENOMEM;
 
-       strcpy(p->alg_name, algo->name);
+       strscpy(p->alg_name, algo->name);
        if (!p->alg_trunc_len)
                p->alg_trunc_len = algo->uinfo.auth.icv_truncbits;
 
@@ -714,7 +714,7 @@ static int attach_aead(struct xfrm_state *x, struct nlattr *rta,
        if (!p)
                return -ENOMEM;
 
-       strcpy(p->alg_name, algo->name);
+       strscpy(p->alg_name, algo->name);
        x->aead = p;
        x->geniv = algo->uinfo.aead.geniv;
        return 0;