Received-SPF: pass (google.com: domain of linux-kernel+bounces-210359-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Date: Tue, 11 Jun 2024 19:52:06 +0200
From: Oscar Salvador <osalvador@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: syzbot <syzbot+569ed13f4054f271087b@syzkaller.appspotmail.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	muchun.song@linux.dev, syzkaller-bugs@googlegroups.com,
	Vivek Kasireddy <vivek.kasireddy@intel.com>
Subject: Re: [syzbot] [mm?] general protection fault in
 dequeue_hugetlb_folio_nodemask (2)
Message-ID: <ZmiOxhiWU-CE2ilg@localhost.localdomain>
References: <0000000000004f12bb061a9acf07@google.com>
 <20240611103005.ae4170608bd15d63adee2492@linux-foundation.org>
 <ZmiNeTL5cZYmCbNf@localhost.localdomain>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ZmiNeTL5cZYmCbNf@localhost.localdomain>

On Tue, Jun 11, 2024 at 07:46:33PM +0200, Oscar Salvador wrote:
> On Tue, Jun 11, 2024 at 10:30:05AM -0700, Andrew Morton wrote:
> > On Tue, 11 Jun 2024 03:34:25 -0700 syzbot <syzbot+569ed13f4054f271087b@syzkaller.appspotmail.com> wrote:
> > 
> > > Hello,
> > > 
> > > syzbot found the following issue on:
> > 
> > Thanks.
> > 
> > > Call Trace:
> > >  <TASK>
> > >  alloc_hugetlb_folio_nodemask+0xae/0x3f0 mm/hugetlb.c:2603
> > >  memfd_alloc_folio+0x15e/0x390 mm/memfd.c:75
> > >  memfd_pin_folios+0x1066/0x1720 mm/gup.c:3864
> > >  udmabuf_create+0x658/0x11c0 drivers/dma-buf/udmabuf.c:353
> > >  udmabuf_ioctl_create drivers/dma-buf/udmabuf.c:420 [inline]
> > >  udmabuf_ioctl+0x304/0x4f0 drivers/dma-buf/udmabuf.c:451
> > >  vfs_ioctl fs/ioctl.c:51 [inline]
> > >  __do_sys_ioctl fs/ioctl.c:907 [inline]
> > >  __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
> > >  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> > >  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> > >  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> > 
> > I think we can pretty confidently point at the series "mm/gup:
> > Introduce memfd_pin_folios() for pinning memfd folios".  I'll drop the
> > v14 series.  
> 
> jfyi: I am trying to reproduce this locally.

Actually, should not memfd_alloc_folio() pass htlb_alloc_mask() instead
of GFP_USER to alloc_hugetlb_folio_nodemask? Or at least do
GFP_HIGHUSER.


-- 
Oscar Salvador
SUSE Labs