On Fri, Dec 31, 2021 at 07:35:07PM +0000, Al Viro wrote:
> On Sat, Jan 01, 2022 at 01:08:41AM +0800, kernel test robot wrote:
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
> > head: a04bbe0a2c7e98669e11a47f94e53dd8228bbeba
> > commit: e95d5bed5d58c2f5352969369827e7135fa2261e [4/5] fs: make d_path-like
functions all have unsigned size
> > config: i386-randconfig-m031-20211228
> > compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp(a)intel.com>
> > smatch warnings:
> > fs/d_path.c:59 prepend() warn: unsigned 'p->len' is never less than
> What do you mean, "unsigned p->len"?
> ->len really *can* be negative - that's how running out of buffer is
> Greg, I stand by the comment I made back in July - this kind of
> useless; there's no legitimate reason to pass a huge buffer length, especially
> since there's a limit on the length of pathname any syscall would accept.
> See https://www.spinics.net/lists/linux-fsdevel/msg200370.html
> variant I would prefer.
Sorry, yes, I agree with you, but never deleted this commit from this
"scratch" branch of mine. I'll go rebase the branch and purge it from
the system so that 0-day doesn't hit it anymore, sorry for the noise.
OK... I'll probably throw something along the lines of "negative => EINVAL,
positive greater than 32Kb - adjust the buffer and length to the last 32Kb
of what had been passed" into the misc queue.