From 252670c421c785127cb55db03c48df5feb57ce12 Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Mon, 10 Nov 2014 15:53:45 +0200 Subject: [PATCH] Bluetooth: Fix sparse warning in amp.c This fixes the following sparse warning: net/bluetooth/amp.c:152:53: warning: Variable length array is used. The warning itself is probably harmless since this kind of usage of shash_desc is present also in other places in the kernel (there's even a convenience macro SHASH_DESC_ON_STACK available for defining such stack variables). However, dynamically allocated versions are also used in several places of the kernel (e.g. kernel/kexec.c and lib/digsig.c) which have the benefit of not exhibiting the sparse warning. Since there are no more sparse warnings in the Bluetooth subsystem after fixing this one it is now easier to spot whenever new ones might get introduced by future patches. Signed-off-by: Johan Hedberg Signed-off-by: Marcel Holtmann --- net/bluetooth/amp.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/net/bluetooth/amp.c b/net/bluetooth/amp.c index 2640d78..ee016f0 100644 --- a/net/bluetooth/amp.c +++ b/net/bluetooth/amp.c @@ -134,6 +134,7 @@ struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr, static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output) { struct crypto_shash *tfm; + struct shash_desc *shash; int ret; if (!ksize) @@ -148,18 +149,24 @@ static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output) ret = crypto_shash_setkey(tfm, key, ksize); if (ret) { BT_DBG("crypto_ahash_setkey failed: err %d", ret); - } else { - char desc[sizeof(struct shash_desc) + - crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR; - struct shash_desc *shash = (struct shash_desc *)desc; - - shash->tfm = tfm; - shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + goto failed; + } - ret = crypto_shash_digest(shash, plaintext, psize, - output); + shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm), + GFP_KERNEL); + if (!shash) { + ret = -ENOMEM; + goto failed; } + shash->tfm = tfm; + shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + ret = crypto_shash_digest(shash, plaintext, psize, output); + + kfree(shash); + +failed: crypto_free_shash(tfm); return ret; } -- 2.7.4