Re: [PATCH v2 0/6] remove dead NULL checks after GFP_NOFAIL allocations and fix xive use-after-free

Leon Romanovsky <[email protected]>
Newsgroups org.ozlabs.lists.linuxppc-dev,org.kernel.vger.linux-kernel,org.kernel.vger.linux-rdma,org.kvack.linux-mm
Message-ID <20260726082419.GF12003@unreal>
On Sat, Jul 25, 2026 at 08:26:32PM -0700, Andrew Morton wrote:
> On Fri, 24 Jul 2026 10:28:45 +0800 Gou Hao <[email protected]> wrote:
> 
> > This is a code cleanup series that removes unreachable
> > NULL checks (and associated error handling) that follow allocations
> > using __GFP_NOFAIL, which guarantees non-NULL return.
> 
> Sigh.
> 
> Back when Linux ran on an abacus, I added __GFP_NOFAIL because four or
> five sites (file systems) were infinitely looping on alloc_pages until
> it succeeded.  I figured we should move this operation into the page
> allocator so we could easily find those sites and fix them to Not Do
> That.
> 
> I made it very clear (changelog and code comments) that no new code
> should use __GFP_NOFAIL.  How did that work out?
> 
> hp2:/usr/src/linux-7.2-rc4> grep -r __GFP_NOFAIL | wc -l
> 241
> 
> So much lameness!   My immediate reaction to your patchset is "No.  Fix
> the damn code instead".  But I've resoundingly lost that fight.
> 
> 
> Thanks, I'll scoop up the entire series.  If individual patches pop up
> in linux-next then I'll drop the mm.git copies.
> 
> 
> 
> AI review has a shower of possible pre-existing issues.  I'm seeing
> use-after-free, double-free, leak, system hang, NULL pointer
> dereference, usual stuff :(
> 
> They're in powerpc and cxgb4, if maintainers are interested.
> 
> 	https://sashiko.dev/#/patchset/[email protected]

Regarding cxgb4, yes, I'm looking into it.

Thanks
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.