lkml.org 
[lkml]   [2019]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] strscpy: reject buffer sizes larger than INT_MAX
As already done for snprintf(), add a check in strscpy() for giant
(i.e. likely negative and/or miscalculated) copy sizes, WARN, and
error out.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
lib/string.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/string.c b/lib/string.c
index 461fb620f85f..913cb945a82a 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -182,7 +182,7 @@ ssize_t strscpy(char *dest, const char *src, size_t count)
size_t max = count;
long res = 0;

- if (count == 0)
+ if (count == 0 || WARN_ON_ONCE(count > INT_MAX))
return -E2BIG;

#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
--
2.17.1

--
Kees Cook

\
 
 \ /
  Last update: 2019-07-26 18:31    [W:0.031 / U:4.644 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site