From 3c3c32f85b6cc05e5db78693457deff03ac0f434 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Fri, 1 May 2020 22:59:45 -0700
Subject: ubifs: fix wrong use of crypto_shash_descsize()
crypto_shash_descsize() returns the size of the shash_desc context
needed to compute the hash, not the size of the hash itself.
crypto_shash_digestsize() would be correct, or alternatively using
c->hash_len and c->hmac_desc_len which already store the correct values.
But actually it's simpler to just use stack arrays, so do that instead.
Fixes: 49525e5eecca ("ubifs: Add helper functions for authentication support")
Fixes: da8ef65f9573 ("ubifs: Authenticate replayed journal")
Cc: <stable@vger.kernel.org> # v4.20+
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
---
fs/ubifs/auth.c | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)
(limited to 'fs/ubifs/auth.c')
diff --git a/fs/ubifs/auth.c b/fs/ubifs/auth.c
index 8cdbd53d780c..f985a3fbbb36 100644
--- a/fs/ubifs/auth.c
+++ b/fs/ubifs/auth.c
@@ -79,13 +79,9 @@ int ubifs_prepare_auth_node(struct ubifs_info *c, void *node,
struct shash_desc *inhash)
{
struct ubifs_auth_node *auth = node;
- u8 *hash;
+ u8 hash[UBIFS_HASH_ARR_SZ];
int err;
- hash = kmalloc(crypto_shash_descsize(c->hash_tfm), GFP_NOFS);
- if (!hash)
- return -ENOMEM;
-
{
SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);
@@ -94,21 +90,16 @@ int ubifs_prepare_auth_node(struct ubifs_info *c, void *node,
err = crypto_shash_final(hash_desc, hash);
if (err)
- goto out;
+ return err;
}
err = ubifs_hash_calc_hmac(c, hash, auth->hmac);
if (err)
- goto out;
+ return err;
auth->ch.node_type = UBIFS_AUTH_NODE;
ubifs_prepare_node(c, auth, ubifs_auth_node_sz(c), 0);
-
- err = 0;
-out:
- kfree(hash);
-
- return err;
+ return 0;
}
static struct shash_desc *ubifs_get_desc(const struct ubifs_info *c,
--
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