Commit 52a0cab3 authored by Kees Cook's avatar Kees Cook Committed by Jens Axboe
Browse files

drbd: Use struct_group() to zero algs 



In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add a struct_group() for the algs so that memset() can correctly reason
about the size.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20211118203712.1288866-1-keescook@chromium.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 322c4293

drivers/block/drbd/drbd_main.c

+2 −1
Original line number Diff line number Diff line
@@ -729,7 +729,8 @@ int drbd_send_sync_param(struct drbd_peer_device *peer_device) 
	cmd = apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;



	/* initialize verify_alg and csums_alg */

	memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);

	BUILD_BUG_ON(sizeof(p->algs) != 2 * SHARED_SECRET_MAX);

	memset(&p->algs, 0, sizeof(p->algs));



	if (get_ldev(peer_device->device)) {

		dc = rcu_dereference(peer_device->device->ldev->disk_conf);

drivers/block/drbd/drbd_protocol.h

+4 −2
Original line number Diff line number Diff line
@@ -283,8 +283,10 @@ struct p_rs_param_89 { 


struct p_rs_param_95 {

	u32 resync_rate;

	struct_group(algs,

		char verify_alg[SHARED_SECRET_MAX];

		char csums_alg[SHARED_SECRET_MAX];

	);

	u32 c_plan_ahead;

	u32 c_delay_target;

	u32 c_fill_target;

drivers/block/drbd/drbd_receiver.c

+2 −1
Original line number Diff line number Diff line
@@ -3921,7 +3921,8 @@ static int receive_SyncParam(struct drbd_connection *connection, struct packet_i 


	/* initialize verify_alg and csums_alg */

	p = pi->data;

	memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);

	BUILD_BUG_ON(sizeof(p->algs) != 2 * SHARED_SECRET_MAX);

	memset(&p->algs, 0, sizeof(p->algs));



	err = drbd_recv_all(peer_device->connection, p, header_size);

	if (err)