From 77ce56e2bfaa64127ae5e23ef136c0168b818777 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 22 Jul 2019 14:26:34 +0200 Subject: drbd: dynamically allocate shash descriptor 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 Reviewed-by: Roland Kammerer Signed-off-by: Arnd Bergmann Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_receiver.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/block') diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 90ebfcae0ce6..2b3103c30857 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -5417,7 +5417,7 @@ 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; @@ -5430,6 +5430,13 @@ 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; rv = crypto_shash_setkey(connection->cram_hmac_tfm, (u8 *)secret, key_len); @@ -5571,7 +5578,10 @@ 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; } -- cgit v1.2.3-55-g7522