lkml.org 
[lkml]   [2018]   [Jun]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH resend] drivers: dma-buf: Change %p to %pK in debug messages
On Tue, Jun 05, 2018 at 04:40:41PM -0700, Daniel Rosenberg wrote:
> The format specifier %p can leak kernel addresses
> while not valuing the kptr_restrict system settings.
> Use %pK instead of %p, which also evaluates whether
> kptr_restrict is set.
>
> Signed-off-by: Divya Ponnusamy <pdivya@codeaurora.org>
> Signed-off-by: Daniel Rosenberg <drosen@google.com>
> Cc: stable <stable@vger.kernel.org>
> ---
> drivers/dma-buf/sync_debug.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
> index c4c8ecb24aa9..d8d340542a79 100644
> --- a/drivers/dma-buf/sync_debug.c
> +++ b/drivers/dma-buf/sync_debug.c
> @@ -133,7 +133,7 @@ static void sync_print_sync_file(struct seq_file *s,
> char buf[128];
> int i;
>
> - seq_printf(s, "[%p] %s: %s\n", sync_file,
> + seq_printf(s, "[%pK] %s: %s\n", sync_file,

This is a root-only file, right? So it's not that bad of a problem.
Also, by default, all %p pointers are now hashed so what really is
leaking here?

And finally, why even print out a pointer at all? Why not just stick
with the name and not worry about the pointer?

thanks,

greg k-h

\
 
 \ /
  Last update: 2018-06-06 11:09    [W:0.053 / U:26.744 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site