Hi,

Eric Sunshine wrote:

> want_color_fd() is designed to work only with standard input, output,
> and error file descriptors, and stores information about each descriptor
> in an array. However, it doesn't verify that the passed-in descriptor
> lives within that set, which, with a buggy caller, could lead to
> access/assignment outside the array bounds.
>
> Signed-off-by: Eric Sunshine <sunsh...@sunshineco.com>
> ---
>  color.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/color.c b/color.c
> index b1c24c69de..b0be9ce505 100644
> --- a/color.c
> +++ b/color.c
> @@ -343,6 +343,9 @@ int want_color_fd(int fd, int var)
>  
>       static int want_auto[3] = { -1, -1, -1 };
>  
> +     if (fd < 0 || fd >= ARRAY_SIZE(want_auto))
> +         BUG("file descriptor out of range: %d", fd);

The indentation looks wrong here.

Combining that with the other suggestions from this thread, I end up
with this v2:

-- >8 --
From: Eric Sunshine <sunsh...@sunshineco.com>
Subject: color: protect against out-of-bounds reads and writes

want_color_fd() is designed to work only with standard output and
error file descriptors and stores information about each descriptor in
an array. However, it doesn't verify that the passed-in descriptor
lives within that set, which, with a buggy caller, could lead to
access or assignment outside the array bounds.

Signed-off-by: Eric Sunshine <sunsh...@sunshineco.com>
Acked-by: Johannes Schindelin <johannes.schinde...@gmx.de>
Signed-off-by: Jonathan Nieder <jrnie...@gmail.com>
---
 color.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/color.c b/color.c
index b1c24c69de..ebb222ec33 100644
--- a/color.c
+++ b/color.c
@@ -343,6 +343,9 @@ int want_color_fd(int fd, int var)
 
        static int want_auto[3] = { -1, -1, -1 };
 
+       if (fd < 1 || fd >= ARRAY_SIZE(want_auto))
+               BUG("file descriptor out of range: %d", fd);
+
        if (var < 0)
                var = git_use_color_default;
 
-- 
2.18.0.597.ga71716f1ad

Reply via email to