Re: [PATCH net-2.6] tcp_probe buffer overflow and incorrect return value

[David Miller <davem@davemloft.net>]

From: Tom Quetchenbach <virtualphtn@gmail.com>
Date: Thu, 24 Apr 2008 14:37:58 -0700

> tcp_probe has a bounds-checking bug that causes many programs (less, python) to
> crash reading /proc/net/tcp_probe. When it outputs a log line to the reader, it
> only checks if that line alone will fit in the reader's buffer, rather than that
> line and all the previous lines it has already written.
> 
> tcpprobe_read also returns the wrong value if copy_to_user fails--it just passes
> on the return value of copy_to_user (number of bytes not copied), which makes a
> failure look like a success.
> 
> This patch fixes the buffer overflow and sets the return value to -EFAULT if
> copy_to_user fails.
> 
> Patch is against latest net-2.6; tested briefly and seems to fix the crashes in
> less and python.
> 
> Signed-off-by: Tom Quetchenbach <virtualphtn@gmail.com>

Thanks a lot for fixing this bug.

I've applied this patch and I'll queue it up for -stable too.

Thanks again.