linux-kernel - [PATCH 3.18 22/58] staging: android: ion: Add __GFP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180223170210.422170320@linuxfoundation.org>
Date:   Fri, 23 Feb 2018 19:26:21 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        syzbot+76e7efc4748495855a4d@...kaller.appspotmail.com,
        syzbot <syzkaller@...glegroups.com>,
        Laura Abbott <labbott@...hat.com>
Subject: [PATCH 3.18 22/58] staging: android: ion: Add __GFP_NOWARN for system contig heap

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Laura Abbott <labbott@...hat.com>

commit 0c75f10312a35b149b2cebb1832316b35c2337ca upstream.

syzbot reported a warning from Ion:

  WARNING: CPU: 1 PID: 3485 at mm/page_alloc.c:3926

  ...
   __alloc_pages_nodemask+0x9fb/0xd80 mm/page_alloc.c:4252
  alloc_pages_current+0xb6/0x1e0 mm/mempolicy.c:2036
  alloc_pages include/linux/gfp.h:492 [inline]
  ion_system_contig_heap_allocate+0x40/0x2c0
  drivers/staging/android/ion/ion_system_heap.c:374
  ion_buffer_create drivers/staging/android/ion/ion.c:93 [inline]
  ion_alloc+0x2c1/0x9e0 drivers/staging/android/ion/ion.c:420
  ion_ioctl+0x26d/0x380 drivers/staging/android/ion/ion-ioctl.c:84
  vfs_ioctl fs/ioctl.c:46 [inline]
  do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
  SYSC_ioctl fs/ioctl.c:701 [inline]
  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692

This is a warning about attempting to allocate order > MAX_ORDER. This
is coming from a userspace Ion allocation request. Since userspace is
free to request however much memory it wants (and the kernel is free to
deny its allocation), silence the allocation attempt with __GFP_NOWARN
in case it fails.

Reported-by: syzbot+76e7efc4748495855a4d@...kaller.appspotmail.com
Reported-by: syzbot <syzkaller@...glegroups.com>
Signed-off-by: Laura Abbott <labbott@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/staging/android/ion/ion_system_heap.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -321,7 +321,7 @@ static int ion_system_contig_heap_alloca
 	if (align > (PAGE_SIZE << order))
 		return -EINVAL;

-	page = alloc_pages(low_order_gfp_flags, order);
+	page = alloc_pages(low_order_gfp_flags | __GFP_NOWARN, order);
 	if (!page)
 		return -ENOMEM;