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

From: Michael Kerrisk (man-pages)
Date: Fri Aug 19 2016 - 16:51:40 EST


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:
>> + if (nr_pages > pipe->buffers) {
>> + if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) {
>
> => if (size > pipe_max_size && !capable(CAP_SYS_RESOURCE)) {
>
>> + 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;
>> + }
>> + }
> (...)

Thanks, Willy. Fixed for the next iteration. (And I made the same fix made
also in the 8/8 patch).

Cheers,

Michael


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