crypto: authenc - Fix zero-length IV crash
As it is if an algorithm with a zero-length IV is used (e.g.,
NULL encryption) with authenc, authenc may generate an SG entry
of length zero, which will trigger a BUG check in the hash layer.
This patch fixes it by skipping the IV SG generation if the IV
size is zero.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/authenc.c b/crypto/authenc.c
index 40b6e9e..5793b64 100644
--- a/crypto/authenc.c
+++ b/crypto/authenc.c
@@ -158,16 +158,19 @@
dstp = sg_page(dst);
vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
- sg_init_table(cipher, 2);
- sg_set_buf(cipher, iv, ivsize);
- authenc_chain(cipher, dst, vdst == iv + ivsize);
+ if (ivsize) {
+ sg_init_table(cipher, 2);
+ sg_set_buf(cipher, iv, ivsize);
+ authenc_chain(cipher, dst, vdst == iv + ivsize);
+ dst = cipher;
+ }
cryptlen = req->cryptlen + ivsize;
- hash = crypto_authenc_hash(req, flags, cipher, cryptlen);
+ hash = crypto_authenc_hash(req, flags, dst, cryptlen);
if (IS_ERR(hash))
return PTR_ERR(hash);
- scatterwalk_map_and_copy(hash, cipher, cryptlen,
+ scatterwalk_map_and_copy(hash, dst, cryptlen,
crypto_aead_authsize(authenc), 1);
return 0;
}
@@ -285,11 +288,14 @@
srcp = sg_page(src);
vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
- sg_init_table(cipher, 2);
- sg_set_buf(cipher, iv, ivsize);
- authenc_chain(cipher, src, vsrc == iv + ivsize);
+ if (ivsize) {
+ sg_init_table(cipher, 2);
+ sg_set_buf(cipher, iv, ivsize);
+ authenc_chain(cipher, src, vsrc == iv + ivsize);
+ src = cipher;
+ }
- return crypto_authenc_verify(req, cipher, cryptlen + ivsize);
+ return crypto_authenc_verify(req, src, cryptlen + ivsize);
}
static int crypto_authenc_decrypt(struct aead_request *req)
