| Message ID | 20190722122647.351002-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drbd: dynamically allocate shash descriptor | expand |
On Mon, Jul 22, 2019 at 02:26:34PM +0200, Arnd Bergmann wrote: > 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/ > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > v2: > - don't try to zero a NULL descriptor pointer, > based on review from Roland Kammerer. > --- > 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 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; > } > -- > 2.20.0 >
On Mon, Jul 22, 2019 at 02:26:34PM +0200, Arnd Bergmann wrote: > 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/ > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Roland Kammerer <roland.kammerer@linbit.com> > --- > v2: > - don't try to zero a NULL descriptor pointer, > based on review from Roland Kammerer. > --- > 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 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; > } > -- > 2.20.0 >
On 7/22/19 6:26 AM, Arnd Bergmann wrote: > 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. Applied, thanks.
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; }
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/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- v2: - don't try to zero a NULL descriptor pointer, based on review from Roland Kammerer. --- drivers/block/drbd/drbd_receiver.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)