Commit 1cb6422e authored by Kees Cook's avatar Kees Cook Committed by David S. Miller
Browse files

ceph: Annotate struct ceph_monmap with __counted_by 

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct ceph_monmap.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci



Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Xiubo Li <xiubli@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: ceph-devel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: default avatarXiubo Li <xiubli@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 02014090

include/linux/ceph/mon_client.h

+1 −1
Original line number Diff line number Diff line
@@ -19,7 +19,7 @@ struct ceph_monmap { 
	struct ceph_fsid fsid;

	u32 epoch;

	u32 num_mon;

	struct ceph_entity_inst mon_inst[];

	struct ceph_entity_inst mon_inst[] __counted_by(num_mon);

};



struct ceph_mon_client;

net/ceph/mon_client.c

+1 −1
Original line number Diff line number Diff line
@@ -1136,6 +1136,7 @@ static int build_initial_monmap(struct ceph_mon_client *monc) 
			       GFP_KERNEL);

	if (!monc->monmap)

		return -ENOMEM;

	monc->monmap->num_mon = num_mon;



	for (i = 0; i < num_mon; i++) {

		struct ceph_entity_inst *inst = &monc->monmap->mon_inst[i];
@@ -1147,7 +1148,6 @@ static int build_initial_monmap(struct ceph_mon_client *monc) 
		inst->name.type = CEPH_ENTITY_TYPE_MON;

		inst->name.num = cpu_to_le64(i);

	}

	monc->monmap->num_mon = num_mon;

	return 0;

}