Re: [PATCH 4/8] pipe: fix limit checking in pipe_set_size()

Hi Willy,

Might you have a chance to further review of this patch series?
It would be great if you could, since much of it touches changes
made by you earlier.

Thanks,

Michael

On 08/19/2016 05:48 PM, Willy Tarreau wrote:

Hi Michael,

Since you're changing this code, it's probably worth swapping the size
check and capable() below to save a function call in the normal path :

On Fri, Aug 19, 2016 at 05:25:35PM +1200, Michael Kerrisk (man-pages) wrote:

quoted

+	if (nr_pages > pipe->buffers) {
+		if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) {

=>		if (size > pipe_max_size && !capable(CAP_SYS_RESOURCE)) {

quoted

+			ret = -EPERM;
+			goto out_revert_acct;
+		} else if ((too_many_pipe_buffers_hard(pipe->user) ||
+				too_many_pipe_buffers_soft(pipe->user)) &&
+				!capable(CAP_SYS_RESOURCE) &&
+				!capable(CAP_SYS_ADMIN)) {
+			ret = -EPERM;
+			goto out_revert_acct;
+		}
+	}

(...)

Cheers,
Willy

-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/