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authorKees Cook <keescook@chromium.org>2021-06-21 15:21:12 -0700
committerDavid S. Miller <davem@davemloft.net>2021-06-22 10:20:51 -0700
commitf2fcffe392c1fd8324f131bf33d7d350eff44bb6 (patch)
treefb85680aff5b1a0069ef6d1ce0bc5974776fe449
parent64a81b24487f0d2fba0f033029eec2abc7d82cee (diff)
hv_netvsc: Avoid field-overflowing memcpy()
In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields. Add flexible array to represent start of buf_info, improving readability and avoid future warning where memcpy() thinks it is writing past the end of the structure. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/hyperv/hyperv_net.h1
-rw-r--r--drivers/net/hyperv/rndis_filter.c6
2 files changed, 3 insertions, 4 deletions
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 442c520ab8f3..9e5eee44f7d3 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1163,6 +1163,7 @@ struct rndis_set_request {
u32 info_buflen;
u32 info_buf_offset;
u32 dev_vc_handle;
+ u8 info_buf[];
};
/* Response to NdisSetRequest */
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index c0e89e107d57..033ed6ed78c5 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1051,10 +1051,8 @@ static int rndis_filter_set_packet_filter(struct rndis_device *dev,
set = &request->request_msg.msg.set_req;
set->oid = RNDIS_OID_GEN_CURRENT_PACKET_FILTER;
set->info_buflen = sizeof(u32);
- set->info_buf_offset = sizeof(struct rndis_set_request);
-
- memcpy((void *)(unsigned long)set + sizeof(struct rndis_set_request),
- &new_filter, sizeof(u32));
+ set->info_buf_offset = offsetof(typeof(*set), info_buf);
+ memcpy(set->info_buf, &new_filter, sizeof(u32));
ret = rndis_filter_send_request(dev, request);
if (ret == 0) {