@@ -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);
@@ -283,8 +283,10 @@ struct p_rs_param_89 {
struct p_rs_param_95 {
u32 resync_rate;
- char verify_alg[SHARED_SECRET_MAX];
- char csums_alg[SHARED_SECRET_MAX];
+ 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;
@@ -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)
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. "objdump -d" shows no changes to the executable instructions. Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: drbd-dev@lists.linbit.com Cc: linux-block@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/block/drbd/drbd_main.c | 3 ++- drivers/block/drbd/drbd_protocol.h | 6 ++++-- drivers/block/drbd/drbd_receiver.c | 3 ++- 3 files changed, 8 insertions(+), 4 deletions(-)