From 762330b161c49c6d88ab689a0ee2a1a959dc5b6b Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 26 Feb 2016 12:44:08 +0100 Subject: [PATCH] Backport fix for crypto: algif_skcipher - Require setkey before accept(2) commit dd504589577d8e8e70f51f997ad487a4cb6c026f upstream. Some cipher implementations will crash if you try to use them without calling setkey first. This patch adds a check so that the accept(2) call will fail with -ENOKEY if setkey hasn't been done on the socket yet. Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov Signed-off-by: Herbert Xu Tested-by: Dmitry Vyukov [backported to 4.1 by Milan Broz ] Signed-off-by: Sasha Levin --- crypto/algif_skcipher.c | 48 +++++++++++++++++++++++++++++++++++------ 1 file changed, 41 insertions(+), 7 deletions(-) diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index 5bc42f9b23f0..1c9879d4a46d 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -31,6 +31,11 @@ struct skcipher_sg_list { struct scatterlist sg[0]; }; +struct skcipher_tfm { + struct crypto_ablkcipher *skcipher; + bool has_key; +}; + struct skcipher_ctx { struct list_head tsgl; struct af_alg_sgl rsgl; @@ -752,17 +757,41 @@ static struct proto_ops algif_skcipher_ops = { static void *skcipher_bind(const char *name, u32 type, u32 mask) { - return crypto_alloc_ablkcipher(name, type, mask); + struct skcipher_tfm *tfm; + struct crypto_ablkcipher *skcipher; + + tfm = kzalloc(sizeof(*tfm), GFP_KERNEL); + if (!tfm) + return ERR_PTR(-ENOMEM); + + skcipher = crypto_alloc_ablkcipher(name, type, mask); + if (IS_ERR(skcipher)) { + kfree(tfm); + return ERR_CAST(skcipher); + } + + tfm->skcipher = skcipher; + + return tfm; } static void skcipher_release(void *private) { - crypto_free_ablkcipher(private); + struct skcipher_tfm *tfm = private; + + crypto_free_ablkcipher(tfm->skcipher); + kfree(tfm); } static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen) { - return crypto_ablkcipher_setkey(private, key, keylen); + struct skcipher_tfm *tfm = private; + int err; + + err = crypto_ablkcipher_setkey(tfm->skcipher, key, keylen); + tfm->has_key = !err; + + return err; } static void skcipher_wait(struct sock *sk) @@ -794,20 +823,25 @@ static int skcipher_accept_parent(void *private, struct sock *sk) { struct skcipher_ctx *ctx; struct alg_sock *ask = alg_sk(sk); - unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(private); + struct skcipher_tfm *tfm = private; + struct crypto_ablkcipher *skcipher = tfm->skcipher; + unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(skcipher); + + if (!tfm->has_key) + return -ENOKEY; ctx = sock_kmalloc(sk, len, GFP_KERNEL); if (!ctx) return -ENOMEM; - ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(private), + ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(skcipher), GFP_KERNEL); if (!ctx->iv) { sock_kfree_s(sk, ctx, len); return -ENOMEM; } - memset(ctx->iv, 0, crypto_ablkcipher_ivsize(private)); + memset(ctx->iv, 0, crypto_ablkcipher_ivsize(skcipher)); INIT_LIST_HEAD(&ctx->tsgl); ctx->len = len; @@ -820,7 +854,7 @@ static int skcipher_accept_parent(void *private, struct sock *sk) ask->private = ctx; - ablkcipher_request_set_tfm(&ctx->req, private); + ablkcipher_request_set_tfm(&ctx->req, skcipher); ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG, af_alg_complete, &ctx->completion);