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authorHerbert Xu <herbert@gondor.apana.org.au>2017-04-10 11:27:57 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2017-04-10 13:09:18 +0200
commitef0579b64e93188710d48667cb5e014926af9f1b (patch)
treea2101da972309a21aa17ab489982c66836924c6f /crypto/ahash.c
parentcrypto: lrw - Fix use-after-free on EINPROGRESS (diff)
downloadlinux-ef0579b64e93188710d48667cb5e014926af9f1b.tar.xz
linux-ef0579b64e93188710d48667cb5e014926af9f1b.zip
crypto: ahash - Fix EINPROGRESS notification callback
The ahash API modifies the request's callback function in order to clean up after itself in some corner cases (unaligned final and missing finup). When the request is complete ahash will restore the original callback and everything is fine. However, when the request gets an EBUSY on a full queue, an EINPROGRESS callback is made while the request is still ongoing. In this case the ahash API will incorrectly call its own callback. This patch fixes the problem by creating a temporary request object on the stack which is used to relay EINPROGRESS back to the original completion function. This patch also adds code to preserve the original flags value. Fixes: ab6bf4e5e5e4 ("crypto: hash - Fix the pointer voodoo in...") Cc: <stable@vger.kernel.org> Reported-by: Sabrina Dubroca <sd@queasysnail.net> Tested-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/ahash.c')
-rw-r--r--crypto/ahash.c79
1 files changed, 50 insertions, 29 deletions
diff --git a/crypto/ahash.c b/crypto/ahash.c
index e58c4970c22b..826cd7ab4d4a 100644
--- a/crypto/ahash.c
+++ b/crypto/ahash.c
@@ -32,6 +32,7 @@ struct ahash_request_priv {
crypto_completion_t complete;
void *data;
u8 *result;
+ u32 flags;
void *ubuf[] CRYPTO_MINALIGN_ATTR;
};
@@ -253,6 +254,8 @@ static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
priv->result = req->result;
priv->complete = req->base.complete;
priv->data = req->base.data;
+ priv->flags = req->base.flags;
+
/*
* WARNING: We do not backup req->priv here! The req->priv
* is for internal use of the Crypto API and the
@@ -267,38 +270,44 @@ static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
return 0;
}
-static void ahash_restore_req(struct ahash_request *req)
+static void ahash_restore_req(struct ahash_request *req, int err)
{
struct ahash_request_priv *priv = req->priv;
+ if (!err)
+ memcpy(priv->result, req->result,
+ crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
+
/* Restore the original crypto request. */
req->result = priv->result;
- req->base.complete = priv->complete;
- req->base.data = priv->data;
+
+ ahash_request_set_callback(req, priv->flags,
+ priv->complete, priv->data);
req->priv = NULL;
/* Free the req->priv.priv from the ADJUSTED request. */
kzfree(priv);
}
-static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
+static void ahash_notify_einprogress(struct ahash_request *req)
{
struct ahash_request_priv *priv = req->priv;
+ struct crypto_async_request oreq;
- if (err == -EINPROGRESS)
- return;
-
- if (!err)
- memcpy(priv->result, req->result,
- crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
+ oreq.data = priv->data;
- ahash_restore_req(req);
+ priv->complete(&oreq, -EINPROGRESS);
}
static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
{
struct ahash_request *areq = req->data;
+ if (err == -EINPROGRESS) {
+ ahash_notify_einprogress(areq);
+ return;
+ }
+
/*
* Restore the original request, see ahash_op_unaligned() for what
* goes where.
@@ -309,7 +318,7 @@ static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
*/
/* First copy req->result into req->priv.result */
- ahash_op_unaligned_finish(areq, err);
+ ahash_restore_req(areq, err);
/* Complete the ORIGINAL request. */
areq->base.complete(&areq->base, err);
@@ -325,7 +334,12 @@ static int ahash_op_unaligned(struct ahash_request *req,
return err;
err = op(req);
- ahash_op_unaligned_finish(req, err);
+ if (err == -EINPROGRESS ||
+ (err == -EBUSY && (ahash_request_flags(req) &
+ CRYPTO_TFM_REQ_MAY_BACKLOG)))
+ return err;
+
+ ahash_restore_req(req, err);
return err;
}
@@ -360,25 +374,14 @@ int crypto_ahash_digest(struct ahash_request *req)
}
EXPORT_SYMBOL_GPL(crypto_ahash_digest);
-static void ahash_def_finup_finish2(struct ahash_request *req, int err)
+static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
{
- struct ahash_request_priv *priv = req->priv;
+ struct ahash_request *areq = req->data;
if (err == -EINPROGRESS)
return;
- if (!err)
- memcpy(priv->result, req->result,
- crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
-
- ahash_restore_req(req);
-}
-
-static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
-{
- struct ahash_request *areq = req->data;
-
- ahash_def_finup_finish2(areq, err);
+ ahash_restore_req(areq, err);
areq->base.complete(&areq->base, err);
}
@@ -389,11 +392,15 @@ static int ahash_def_finup_finish1(struct ahash_request *req, int err)
goto out;
req->base.complete = ahash_def_finup_done2;
- req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+
err = crypto_ahash_reqtfm(req)->final(req);
+ if (err == -EINPROGRESS ||
+ (err == -EBUSY && (ahash_request_flags(req) &
+ CRYPTO_TFM_REQ_MAY_BACKLOG)))
+ return err;
out:
- ahash_def_finup_finish2(req, err);
+ ahash_restore_req(req, err);
return err;
}
@@ -401,7 +408,16 @@ static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
{
struct ahash_request *areq = req->data;
+ if (err == -EINPROGRESS) {
+ ahash_notify_einprogress(areq);
+ return;
+ }
+
+ areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+
err = ahash_def_finup_finish1(areq, err);
+ if (areq->priv)
+ return;
areq->base.complete(&areq->base, err);
}
@@ -416,6 +432,11 @@ static int ahash_def_finup(struct ahash_request *req)
return err;
err = tfm->update(req);
+ if (err == -EINPROGRESS ||
+ (err == -EBUSY && (ahash_request_flags(req) &
+ CRYPTO_TFM_REQ_MAY_BACKLOG)))
+ return err;
+
return ahash_def_finup_finish1(req, err);
}