drbd: dynamically allocate shash descriptor

[ Upstream commit 77ce56e2bf ]

Building with clang and KASAN, we get a warning about an overly large
stack frame on 32-bit architectures:

drivers/block/drbd/drbd_receiver.c:921:31: error: stack frame size of 1280 bytes in function 'conn_connect'
      [-Werror,-Wframe-larger-than=]

We already allocate other data dynamically in this function, so
just do the same for the shash descriptor, which makes up most of
this memory.

Link: https://lore.kernel.org/lkml/20190617132440.2721536-1-arnd@arndb.de/
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Arnd Bergmann 2019-07-22 14:26:34 +02:00 committed by Greg Kroah-Hartman
parent f4e2d182d6
commit 38c919ec7b

View file

@ -5240,7 +5240,7 @@ static int drbd_do_auth(struct drbd_connection *connection)
unsigned int key_len;
char secret[SHARED_SECRET_MAX]; /* 64 byte */
unsigned int resp_size;
SHASH_DESC_ON_STACK(desc, connection->cram_hmac_tfm);
struct shash_desc *desc;
struct packet_info pi;
struct net_conf *nc;
int err, rv;
@ -5253,6 +5253,13 @@ static int drbd_do_auth(struct drbd_connection *connection)
memcpy(secret, nc->shared_secret, key_len);
rcu_read_unlock();
desc = kmalloc(sizeof(struct shash_desc) +
crypto_shash_descsize(connection->cram_hmac_tfm),
GFP_KERNEL);
if (!desc) {
rv = -1;
goto fail;
}
desc->tfm = connection->cram_hmac_tfm;
desc->flags = 0;
@ -5395,7 +5402,10 @@ static int drbd_do_auth(struct drbd_connection *connection)
kfree(peers_ch);
kfree(response);
kfree(right_response);
shash_desc_zero(desc);
if (desc) {
shash_desc_zero(desc);
kfree(desc);
}
return rv;
}