linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: linux-hardening@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>
Subject: [PATCH 2/3][next] lib/stackdepot.c: Use flex_array_size() helper in memcpy()
Date: Thu, 1 Oct 2020 10:25:42 -0500	[thread overview]
Message-ID: <186e37fe07196ee41a0e562fa8a8cb7a01112ec5.1601565471.git.gustavoars@kernel.org> (raw)
In-Reply-To: <cover.1601565471.git.gustavoars@kernel.org>

Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer
overflows, while at the same time makes it explicitly clear that
we are dealing with a flexible array member.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 lib/stackdepot.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index c6106cfb7950..683b6a8ddade 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -135,7 +135,7 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size,
 	stack->handle.slabindex = depot_index;
 	stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN;
 	stack->handle.valid = 1;
-	memcpy(stack->entries, entries, size * sizeof(unsigned long));
+	memcpy(stack->entries, entries, flex_array_size(stack, entries, size));
 	depot_offset += required_size;
 
 	return stack;
-- 
2.27.0


  parent reply	other threads:[~2020-10-01 15:19 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-01 15:24 [PATCH 0/3][next] lib/stackdepot.c: Replace one-element array with flexible-array member Gustavo A. R. Silva
2020-10-01 15:25 ` [PATCH 1/3][next] " Gustavo A. R. Silva
2020-10-01 15:25 ` Gustavo A. R. Silva [this message]
2020-10-01 15:26 ` [PATCH 3/3][next] lib/stackdepot.c: Use array_size() helper in jhash2() Gustavo A. R. Silva

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=186e37fe07196ee41a0e562fa8a8cb7a01112ec5.1601565471.git.gustavoars@kernel.org \
    --to=gustavoars@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).