diff mbox series

hv_netvsc: Avoid field-overflowing memcpy()

Message ID 20210621222112.1749650-1-keescook@chromium.org (mailing list archive)
State Accepted
Commit f2fcffe392c1fd8324f131bf33d7d350eff44bb6
Delegated to: Netdev Maintainers
Headers show
Series hv_netvsc: Avoid field-overflowing memcpy() | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Guessed tree name to be net-next
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 19 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

Kees Cook June 21, 2021, 10:21 p.m. UTC
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>
---
 drivers/net/hyperv/hyperv_net.h   | 1 +
 drivers/net/hyperv/rndis_filter.c | 6 ++----
 2 files changed, 3 insertions(+), 4 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org June 22, 2021, 5:30 p.m. UTC | #1
Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Mon, 21 Jun 2021 15:21:12 -0700 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - hv_netvsc: Avoid field-overflowing memcpy()
    https://git.kernel.org/netdev/net-next/c/f2fcffe392c1

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
diff mbox series

Patch

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index b11aa68b44ec..bc48855dff10 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1170,6 +1170,7 @@  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 983bf362466a..f6c9c2a670f9 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) {