Re: [PATCH] color: protect against out-of-bounds array access/assignment
- From
Jonathan Nieder <jrnieder@gmail.com>
- Date
- Aug 3, 2018, 06:07 UTC
- Message-ID
- <20180803060749.GA237521@aiede.svl.corp.google.com>
- In-Reply-To
- <20180802093208.27420-1-sunshine@sunshineco.com>
Hi,
Eric Sunshine wrote:
Show 21 quoted lines
> 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 <sunshine@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 <sunshine@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 <sunshine@sunshineco.com> Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Jonathan Nieder <jrnieder@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