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From: Kees Cook <keescook@chromium.org>
To: Jiri Slaby <jslaby@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>, Jann Horn <jannh@google.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Christoph Hellwig <hch@infradead.org>,
	Christopher Lameter <cl@linux.com>,
	Julian Wiedmann <jwi@linux.ibm.com>,
	Ursula Braun <ubraun@linux.ibm.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	kernel list <linux-kernel@vger.kernel.org>,
	David Windsor <dave@nullcore.net>,
	Pekka Enberg <penberg@kernel.org>,
	David Rientjes <rientjes@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux-MM <linux-mm@kvack.org>,
	linux-xfs@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andy Lutomirski <luto@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Laura Abbott <labbott@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Christoffer Dall <christoffer.dall@linaro.org>,
	Dave Kleikamp <dave.kleikamp@oracle.com>, Jan Kara <jack@suse.cz>,
	Luis de Bethencourt <luisbg@kernel.org>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Rik van Riel <riel@redhat.com>,
	Matthew Garrett <mjg59@google.com>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-arch <linux-arch@vger.kernel.org>,
	Network Development <netdev@vger.kernel.org>,
	Kernel Hardening <kernel-hardening@lists.openwall.com>,
	Michal Kubecek <mkubecek@suse.cz>
Subject: Re: [kernel-hardening] [PATCH 09/38] usercopy: Mark kmalloc caches as usercopy caches
Date: Mon, 20 Apr 2020 10:43:37 -0700	[thread overview]
Message-ID: <202004201043.538A7B3F2@keescook> (raw)
In-Reply-To: <548e6212-7b3c-5925-19f2-699af451fd16@suse.cz>

On Mon, Apr 20, 2020 at 09:53:20AM +0200, Jiri Slaby wrote:
> On 07. 04. 20, 10:00, Vlastimil Babka wrote:
> > From d5190e4e871689a530da3c3fd327be45a88f006a Mon Sep 17 00:00:00 2001
> > From: Vlastimil Babka <vbabka@suse.cz>
> > Date: Tue, 7 Apr 2020 09:58:00 +0200
> > Subject: [PATCH] usercopy: Mark dma-kmalloc caches as usercopy caches
> > 
> > We have seen a "usercopy: Kernel memory overwrite attempt detected to SLUB
> > object 'dma-kmalloc-1 k' (offset 0, size 11)!" error on s390x, as IUCV uses
> > kmalloc() with __GFP_DMA because of memory address restrictions.
> > The issue has been discussed [2] and it has been noted that if all the kmalloc
> > caches are marked as usercopy, there's little reason not to mark dma-kmalloc
> > caches too. The 'dma' part merely means that __GFP_DMA is used to restrict
> > memory address range.
> > 
> > As Jann Horn put it [3]:
> > 
> > "I think dma-kmalloc slabs should be handled the same way as normal
> > kmalloc slabs. When a dma-kmalloc allocation is freshly created, it is
> > just normal kernel memory - even if it might later be used for DMA -,
> > and it should be perfectly fine to copy_from_user() into such
> > allocations at that point, and to copy_to_user() out of them at the
> > end. If you look at the places where such allocations are created, you
> > can see things like kmemdup(), memcpy() and so on - all normal
> > operations that shouldn't conceptually be different from usercopy in
> > any relevant way."
> > 
> > Thus this patch marks the dma-kmalloc-* caches as usercopy.
> > 
> > [1] https://bugzilla.suse.com/show_bug.cgi?id=1156053
> > [2] https://lore.kernel.org/kernel-hardening/bfca96db-bbd0-d958-7732-76e36c667c68@suse.cz/
> > [3] https://lore.kernel.org/kernel-hardening/CAG48ez1a4waGk9kB0WLaSbs4muSoK0AYAVk8=XYaKj4_+6e6Hg@mail.gmail.com/
> > 
> > Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> 
> Friendly ping.
> 
> Acked-by: Jiri Slaby <jslaby@suse.cz>

Should this go via -mm?

-Kees

> 
> > ---
> >  mm/slab_common.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/mm/slab_common.c b/mm/slab_common.c
> > index 5282f881d2f5..ae9486160594 100644
> > --- a/mm/slab_common.c
> > +++ b/mm/slab_common.c
> > @@ -1303,7 +1303,8 @@ void __init create_kmalloc_caches(slab_flags_t flags)
> >  			kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache(
> >  				kmalloc_info[i].name[KMALLOC_DMA],
> >  				kmalloc_info[i].size,
> > -				SLAB_CACHE_DMA | flags, 0, 0);
> > +				SLAB_CACHE_DMA | flags, 0,
> > +				kmalloc_info[i].size);
> >  		}
> >  	}
> >  #endif
> > 
> 
> thanks,
> -- 
> js
> suse labs

-- 
Kees Cook


  reply	other threads:[~2020-04-20 17:43 UTC|newest]

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-11  2:02 [PATCH v5 00/38] Hardened usercopy whitelisting Kees Cook
2018-01-11  2:02 ` [PATCH 01/38] usercopy: Remove pointer from overflow report Kees Cook
2018-01-11  2:02 ` [PATCH 02/38] usercopy: Enhance and rename report_usercopy() Kees Cook
2018-01-11 17:06   ` Christopher Lameter
2018-01-14 20:57     ` Kees Cook
2018-01-11  2:02 ` [PATCH 03/38] usercopy: Include offset in hardened usercopy report Kees Cook
2018-01-11  2:02 ` [PATCH 04/38] lkdtm/usercopy: Adjust test to include an offset to check reporting Kees Cook
2018-01-11  2:02 ` [PATCH 05/38] stddef.h: Introduce sizeof_field() Kees Cook
2018-01-11  2:02 ` [PATCH 06/38] usercopy: Prepare for usercopy whitelisting Kees Cook
2018-01-11  2:02 ` [PATCH 07/38] usercopy: WARN() on slab cache usercopy region violations Kees Cook
2018-01-11  2:02 ` [PATCH 08/38] usercopy: Allow strict enforcement of whitelists Kees Cook
2018-01-11  2:02 ` [PATCH 09/38] usercopy: Mark kmalloc caches as usercopy caches Kees Cook
2019-11-12  7:17   ` [kernel-hardening] " Jiri Slaby
2019-11-12 21:21     ` Kees Cook
2019-11-14 21:27       ` Kees Cook
2020-01-23  8:14         ` Jiri Slaby
2020-01-27 23:19           ` Kees Cook
2020-01-28  7:58             ` Christian Borntraeger
2020-01-28 23:01               ` Kees Cook
2020-01-29  9:26                 ` Ursula Braun
2020-01-29 16:43                 ` Christopher Lameter
2020-01-29 17:07                   ` Christian Borntraeger
2020-01-29 17:09                     ` Christoph Hellwig
2020-01-29 17:19                       ` Christian Borntraeger
2020-01-30 19:23                         ` Kees Cook
2020-01-31 12:03                           ` Jann Horn
2020-02-01 17:56                             ` Kees Cook
2020-02-01 19:27                               ` Jann Horn
2020-02-03  7:46                                 ` Matthew Wilcox
2020-02-03 17:41                                   ` Christoph Hellwig
2020-02-03 17:20                               ` Christopher Lameter
2020-04-07  8:00                             ` Vlastimil Babka
2020-04-07 11:05                               ` Christian Borntraeger
2020-04-20  7:53                               ` Jiri Slaby
2020-04-20 17:43                                 ` Kees Cook [this message]
2020-02-03 17:38                           ` Christoph Hellwig
2020-02-03 17:36                         ` Christoph Hellwig
2018-01-11  2:02 ` [PATCH 10/38] dcache: Define usercopy region in dentry_cache slab cache Kees Cook
2018-01-11  2:02 ` [PATCH 11/38] vfs: Define usercopy region in names_cache slab caches Kees Cook
2018-01-11  2:02 ` [PATCH 12/38] vfs: Copy struct mount.mnt_id to userspace using put_user() Kees Cook
2018-01-11  2:02 ` [PATCH 13/38] ext4: Define usercopy region in ext4_inode_cache slab cache Kees Cook
2018-01-11 17:01   ` Theodore Ts'o
2018-01-11 23:05     ` Kees Cook
2018-01-14 22:34       ` Matthew Wilcox
2018-01-11  2:02 ` [PATCH 14/38] ext2: Define usercopy region in ext2_inode_cache " Kees Cook
2018-01-11  2:02 ` [PATCH 15/38] jfs: Define usercopy region in jfs_ip " Kees Cook
2018-01-11  2:02 ` [PATCH 16/38] befs: Define usercopy region in befs_inode_cache " Kees Cook
2018-01-11  2:02 ` [PATCH 17/38] exofs: Define usercopy region in exofs_inode_cache " Kees Cook
2018-01-11  2:02 ` [PATCH 18/38] orangefs: Define usercopy region in orangefs_inode_cache " Kees Cook
2018-01-11  2:02 ` [PATCH 19/38] ufs: Define usercopy region in ufs_inode_cache " Kees Cook
2018-01-11  2:02 ` [PATCH 20/38] vxfs: Define usercopy region in vxfs_inode " Kees Cook
2018-01-11  2:02 ` [PATCH 21/38] cifs: Define usercopy region in cifs_request " Kees Cook
2018-01-11  2:02 ` [PATCH 22/38] scsi: Define usercopy region in scsi_sense_cache " Kees Cook
2018-01-11  2:02 ` [PATCH 23/38] net: Define usercopy region in struct proto " Kees Cook
2018-01-11  2:02 ` [PATCH 24/38] ip: Define usercopy region in IP " Kees Cook
2018-01-11  2:02 ` [PATCH 25/38] caif: Define usercopy region in caif " Kees Cook
2018-01-11  2:02 ` [PATCH 26/38] sctp: Define usercopy region in SCTP " Kees Cook
2018-01-11  2:02 ` [PATCH 27/38] sctp: Copy struct sctp_sock.autoclose to userspace using put_user() Kees Cook
2018-01-18 21:31   ` Laura Abbott
2018-01-18 21:36     ` Kees Cook
2018-01-11  2:03 ` [PATCH 28/38] net: Restrict unwhitelisted proto caches to size 0 Kees Cook
2018-01-11  2:03 ` [PATCH 29/38] fork: Define usercopy region in mm_struct slab caches Kees Cook
2018-01-11  2:03 ` [PATCH 30/38] fork: Define usercopy region in thread_stack " Kees Cook
2018-01-11  2:03 ` [PATCH 31/38] fork: Provide usercopy whitelisting for task_struct Kees Cook
2018-01-11  2:03 ` [PATCH 32/38] x86: Implement thread_struct whitelist for hardened usercopy Kees Cook
2018-01-11  2:03 ` [PATCH 33/38] arm64: " Kees Cook
2018-01-15 12:24   ` Dave P Martin
2018-01-15 20:06     ` Kees Cook
2018-01-16 12:33       ` Dave Martin
2018-01-11  2:03 ` [PATCH 34/38] arm: " Kees Cook
2018-01-11 10:24   ` Russell King - ARM Linux
2018-01-11 23:21     ` Kees Cook
2018-01-11  2:03 ` [PATCH 35/38] kvm: whitelist struct kvm_vcpu_arch Kees Cook
2018-01-11  2:03 ` [PATCH 36/38] kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl Kees Cook
2018-01-11  2:03 ` [PATCH 37/38] usercopy: Restrict non-usercopy caches to size 0 Kees Cook
2018-01-11  2:03 ` [PATCH 38/38] lkdtm: Update usercopy tests for whitelisting Kees Cook

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