[ Upstream commit 77ce56e2bfaa64127ae5e23ef136c0168b818777 ]
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 --- drivers/block/drbd/drbd_receiver.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index cb919b9640660..3cdadf75c82da 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -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; }