crypto: algif_skcipher - Handle unaligned receive buffer

As it is if user-space passes through a receive buffer that's not aligned to to the cipher block size, we'll end up encrypting or decrypting a partial block which causes a spurious EINVAL to be returned. This patch fixes this by moving the partial block test after the af_alg_make_sg call. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: algif_skcipher - Handle unaligned receive buffer
As it is if user-space passes through a receive buffer that's not aligned to to the cipher block size, we'll end up encrypting or decrypting a partial block which causes a spurious EINVAL to be returned. This patch fixes this by moving the partial block test after the af_alg_make_sg call. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Herbert Xu
1 parent 0f6bb83cb1
Showing 1 changed file with 7 additions and 6 deletions Side-by-side Diff
crypto/algif_skcipher.c
@@ -454,18 +454,18 @@
  
 			used = min_t(unsigned long, used, seglen);
  
+			used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
+			err = used;
+			if (err < 0)
+				goto unlock;
+
 			if (ctx->more || used < ctx->used)
 				used -= used % bs;
  
 			err = -EINVAL;
 			if (!used)
-				goto unlock;
+				goto free;
  
-			used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
-			err = used;
-			if (err < 0)
-				goto unlock;
-
 			ablkcipher_request_set_crypt(&ctx->req, sg,
 						     ctx->rsgl.sg, used,
 						     ctx->iv);
@@ -476,6 +476,7 @@
 					crypto_ablkcipher_decrypt(&ctx->req),
 				&ctx->completion);
  
+free:
 			af_alg_free_sg(&ctx->rsgl);
  
 			if (err)
...	...	@@ -454,18 +454,18 @@
454	454
455	455	used = min_t(unsigned long, used, seglen);
456	456
	457	+ used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
	458	+ err = used;
	459	+ if (err < 0)
	460	+ goto unlock;
	461	+
457	462	if (ctx->more \|\| used < ctx->used)
458	463	used -= used % bs;
459	464
460	465	err = -EINVAL;
461	466	if (!used)
462		- goto unlock;
	467	+ goto free;
463	468
464		- used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
465		- err = used;
466		- if (err < 0)
467		- goto unlock;
468		-
469	469	ablkcipher_request_set_crypt(&ctx->req, sg,
470	470	ctx->rsgl.sg, used,
471	471	ctx->iv);
...	...	@@ -476,6 +476,7 @@
476	476	crypto_ablkcipher_decrypt(&ctx->req),
477	477	&ctx->completion);
478	478
	479	+free:
479	480	af_alg_free_sg(&ctx->rsgl);
480	481
481	482	if (err)