crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption

jira KERNEL-949
cve CVE-2026-31431
Rebuild_History Non-Buildable kernel-4.18.0-553.123.1.el8_10
commit-author Herbert Xu <herbert@gondor.apana.org.au>
commit e024941
Empty-Commit: Cherry-Pick Conflicts during history rebuild.
Will be included in final tarball splat. Ref for failed cherry-pick at:
ciq/ciq_backports/kernel-4.18.0-553.123.1.el8_10/e0249411.failed

When decrypting data that is not in-place (src != dst), there is
no need to save the high-order sequence bits in dst as it could
simply be re-copied from the source.

However, the data to be hashed need to be rearranged accordingly.

	Reported-by: Taeyang Lee <0wn@theori.io>
Fixes: 104880a ("crypto: authencesn - Convert to new AEAD interface")
	Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Thanks,

	Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit e024941)
	Signed-off-by: Jonathan Maple <jmaple@ciq.com>

# Conflicts:
#	crypto/authencesn.c

Author: PlaidCat

ciq/ciq_backports/kernel-4.18.0-553.123.1.el8_10/e0249411.failed

@@ -0,0 +1,68 @@
+crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption
+
+jira KERNEL-949
+cve CVE-2026-31431
+Rebuild_History Non-Buildable kernel-4.18.0-553.123.1.el8_10
+commit-author Herbert Xu <herbert@gondor.apana.org.au>
+commit e02494114ebf7c8b42777c6cd6982f113bfdbec7
+Empty-Commit: Cherry-Pick Conflicts during history rebuild.
+Will be included in final tarball splat. Ref for failed cherry-pick at:
+ciq/ciq_backports/kernel-4.18.0-553.123.1.el8_10/e0249411.failed
+
+When decrypting data that is not in-place (src != dst), there is
+no need to save the high-order sequence bits in dst as it could
+simply be re-copied from the source.
+
+However, the data to be hashed need to be rearranged accordingly.
+
+	Reported-by: Taeyang Lee <0wn@theori.io>
+Fixes: 104880a6b470 ("crypto: authencesn - Convert to new AEAD interface")
+	Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+
+Thanks,
+
+	Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+(cherry picked from commit e02494114ebf7c8b42777c6cd6982f113bfdbec7)
+	Signed-off-by: Jonathan Maple <jmaple@ciq.com>
+
+# Conflicts:
+#	crypto/authencesn.c
+diff --cc crypto/authencesn.c
+index a7c345f88223,c0a01d738d9b..000000000000
+--- a/crypto/authencesn.c
++++ b/crypto/authencesn.c
+@@@ -244,10 -204,10 +244,11 @@@ static int crypto_authenc_esn_decrypt_t
+  	struct skcipher_request *skreq = (void *)(areq_ctx->tail +
+  						  ctx->reqoff);
+  	struct crypto_ahash *auth = ctx->auth;
+ -	u8 *ohash = areq_ctx->tail;
+ +	u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail,
+ +			      crypto_ahash_alignmask(auth) + 1);
+  	unsigned int cryptlen = req->cryptlen - authsize;
+  	unsigned int assoclen = req->assoclen;
++ 	struct scatterlist *src = req->src;
+  	struct scatterlist *dst = req->dst;
+  	u8 *ihash = ohash + crypto_ahash_digestsize(auth);
+  	u32 tmp[2];
+@@@ -305,17 -268,6 +311,20 @@@ static int crypto_authenc_esn_decrypt(s
+  	if (assoclen < 8)
+  		return -EINVAL;
+  
+++<<<<<<< HEAD
+ +	cryptlen -= authsize;
+ +
+ +	if (req->src != dst) {
+ +		err = crypto_authenc_esn_copy(req, assoclen + cryptlen);
+ +		if (err)
+ +			return err;
+ +	}
+ +
+ +	scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen,
+ +				 authsize, 0);
+ +
+++=======
+++>>>>>>> e02494114ebf (crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption)
+  	if (!authsize)
+  		goto tail;
+  
+* Unmerged path crypto/authencesn.c