crypto: seqiv - Do not use req->iv after crypto_aead_encrypt

[ Upstream commit 50fdb78b7c0bcc550910ef69c0984e751cac72fa ]

As soon as crypto_aead_encrypt is called, the underlying request
may be freed by an asynchronous completion.  Thus dereferencing
req->iv after it returns is invalid.

Instead of checking req->iv against info, create a new variable
unaligned_info and use it for that purpose instead.

Fixes: 0a270321dbf9 ("[CRYPTO] seqiv: Add Sequence Number IV Generator")
Reported-by: Xiumei Mu <xmu@redhat.com>
Reported-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/crypto/seqiv.c b/crypto/seqiv.c
index b1bcfe537daf11059aeef1c8aae7b04c2b05641a..562ab102226ab241f44dd1bb95d4bcf6f9d0a14d 100644 (file)
--- a/crypto/seqiv.c
+++ b/crypto/seqiv.c
@@ -51,6 +51,7 @@ static int seqiv_aead_encrypt(struct aead_request *req)
        struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
        struct aead_request *subreq = aead_request_ctx(req);
        crypto_completion_t compl;
+       bool unaligned_info;
        void *data;
        u8 *info;
        unsigned int ivsize = 8;
@@ -80,8 +81,9 @@ static int seqiv_aead_encrypt(struct aead_request *req)
                        return err;
        }
 
-       if (unlikely(!IS_ALIGNED((unsigned long)info,
-                                crypto_aead_alignmask(geniv) + 1))) {
+       unaligned_info = !IS_ALIGNED((unsigned long)info,
+                                    crypto_aead_alignmask(geniv) + 1);
+       if (unlikely(unaligned_info)) {
                info = kmemdup(req->iv, ivsize, req->base.flags &
                               CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
                               GFP_ATOMIC);
@@ -101,7 +103,7 @@ static int seqiv_aead_encrypt(struct aead_request *req)
        scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
 
        err = crypto_aead_encrypt(subreq);
-       if (unlikely(info != req->iv))
+       if (unlikely(unaligned_info))
                seqiv_aead_encrypt_complete2(req, err);
        return err;
 }