From: Miguel García <miguelgarciaroman8@gmail.com>
Date: Thu, 14 Aug 2025 19:32:17 +0000 (+0200)
Subject: xfrm: xfrm_user: use strscpy() for alg_name
X-Git-Tag: v6.18-rc1~132^2~55^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9f4f591cd5a410f4203a9c104f92d467945b7d7e;p=thirdparty%2Flinux.git

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 684239018bec4..010c9e6638c0c 100644
--- 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;