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From: Christopher Lameter <cl@linux.com>
To: Kees Cook <keescook@chromium.org>
Cc: 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>,
	Laura Abbott <labbott@redhat.com>, Ingo Molnar <mingo@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-mm@kvack.org, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org,
	kernel-hardening@lists.openwall.com
Subject: Re: [PATCH v3 02/31] usercopy: Enforce slab cache usercopy region boundaries
Date: Thu, 21 Sep 2017 10:23:45 -0500 (CDT)	[thread overview]
Message-ID: <alpine.DEB.2.20.1709211022550.14427@nuc-kabylake> (raw)
In-Reply-To: <1505940337-79069-3-git-send-email-keescook@chromium.org>

On Wed, 20 Sep 2017, Kees Cook wrote:

> diff --git a/mm/slab.c b/mm/slab.c
> index 87b6e5e0cdaf..df268999cf02 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -4408,7 +4408,9 @@ module_init(slab_proc_init);
>
>  #ifdef CONFIG_HARDENED_USERCOPY
>  /*
> - * Rejects objects that are incorrectly sized.
> + * Rejects incorrectly sized objects and objects that are to be copied
> + * to/from userspace but do not fall entirely within the containing slab
> + * cache's usercopy region.
>   *
>   * Returns NULL if check passes, otherwise const char * to name of cache
>   * to indicate an error.
> @@ -4428,11 +4430,15 @@ const char *__check_heap_object(const void *ptr, unsigned long n,
>  	/* Find offset within object. */
>  	offset = ptr - index_to_obj(cachep, page, objnr) - obj_offset(cachep);
>
> -	/* Allow address range falling entirely within object size. */
> -	if (offset <= cachep->object_size && n <= cachep->object_size - offset)
> -		return NULL;
> +	/* Make sure object falls entirely within cache's usercopy region. */
> +	if (offset < cachep->useroffset)
> +		return cachep->name;
> +	if (offset - cachep->useroffset > cachep->usersize)
> +		return cachep->name;
> +	if (n > cachep->useroffset - offset + cachep->usersize)
> +		return cachep->name;
>
> -	return cachep->name;
> +	return NULL;
>  }
>  #endif /* CONFIG_HARDENED_USERCOPY */

Looks like this is almost the same for all allocators. Can we put this
into mm/slab_common.c?

  reply	other threads:[~2017-09-21 15:23 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-20 20:45 [PATCH v3 00/31] Hardened usercopy whitelisting Kees Cook
2017-09-20 20:45 ` [PATCH v3 01/31] usercopy: Prepare for " Kees Cook
2017-09-21 15:21   ` Christopher Lameter
2017-09-20 20:45 ` [PATCH v3 02/31] usercopy: Enforce slab cache usercopy region boundaries Kees Cook
2017-09-21 15:23   ` Christopher Lameter [this message]
2017-09-20 20:45 ` [PATCH v3 03/31] usercopy: Mark kmalloc caches as usercopy caches Kees Cook
2017-09-21 15:27   ` Christopher Lameter
2017-09-21 15:40     ` [kernel-hardening] " Kees Cook
2017-09-21 16:04       ` Christopher Lameter
2017-09-21 18:26         ` Kees Cook
2017-09-20 20:45 ` [PATCH v3 04/31] dcache: Define usercopy region in dentry_cache slab cache Kees Cook
2017-09-20 20:45 ` [PATCH v3 05/31] vfs: Define usercopy region in names_cache slab caches Kees Cook
2017-09-20 20:45 ` [PATCH v3 06/31] vfs: Copy struct mount.mnt_id to userspace using put_user() Kees Cook
2017-09-20 20:45 ` [PATCH v3 07/31] ext4: Define usercopy region in ext4_inode_cache slab cache Kees Cook
2017-09-20 20:45 ` [PATCH v3 08/31] ext2: Define usercopy region in ext2_inode_cache " Kees Cook
2017-09-20 20:45 ` [PATCH v3 09/31] jfs: Define usercopy region in jfs_ip " Kees Cook
2017-09-22  2:54   ` Dave Kleikamp
2017-09-20 20:45 ` [PATCH v3 10/31] befs: Define usercopy region in befs_inode_cache " Kees Cook
2017-09-21  9:34   ` Luis de Bethencourt
2017-09-20 20:45 ` [PATCH v3 11/31] exofs: Define usercopy region in exofs_inode_cache " Kees Cook
2017-09-20 20:45 ` [PATCH v3 12/31] orangefs: Define usercopy region in orangefs_inode_cache " Kees Cook
2017-09-20 20:45 ` [PATCH v3 13/31] ufs: Define usercopy region in ufs_inode_cache " Kees Cook
2017-09-20 20:45 ` [PATCH v3 14/31] vxfs: Define usercopy region in vxfs_inode " Kees Cook
2017-09-20 20:56   ` Christoph Hellwig
2017-09-20 21:21     ` Kees Cook
2017-09-20 23:22       ` Christoph Hellwig
2017-09-20 20:45 ` [PATCH v3 15/31] xfs: Define usercopy region in xfs_inode " Kees Cook
2017-09-20 20:45 ` [PATCH v3 16/31] cifs: Define usercopy region in cifs_request " Kees Cook
2017-09-20 20:45 ` [PATCH v3 17/31] scsi: Define usercopy region in scsi_sense_cache " Kees Cook
2017-09-20 20:45 ` [PATCH v3 18/31] net: Define usercopy region in struct proto " Kees Cook
2017-09-20 20:45 ` [PATCH v3 19/31] ip: Define usercopy region in IP " Kees Cook
2017-09-20 20:45 ` [PATCH v3 20/31] caif: Define usercopy region in caif " Kees Cook
2017-09-20 20:45 ` [PATCH v3 21/31] sctp: Define usercopy region in SCTP " Kees Cook
2017-09-20 20:45 ` [PATCH v3 22/31] sctp: Copy struct sctp_sock.autoclose to userspace using put_user() Kees Cook
2017-09-20 20:45 ` [PATCH v3 23/31] net: Restrict unwhitelisted proto caches to size 0 Kees Cook
2017-09-20 20:45 ` [PATCH v3 24/31] fork: Define usercopy region in mm_struct slab caches Kees Cook
2017-09-20 20:45 ` [PATCH v3 25/31] fork: Define usercopy region in thread_stack " Kees Cook
2017-09-20 20:45 ` [PATCH v3 26/31] fork: Provide usercopy whitelisting for task_struct Kees Cook
2017-09-20 20:45 ` [PATCH v3 27/31] x86: Implement thread_struct whitelist for hardened usercopy Kees Cook
2017-09-20 20:45 ` [PATCH v3 28/31] arm64: " Kees Cook
2017-09-20 20:45 ` [PATCH v3 29/31] arm: " Kees Cook
2017-09-20 20:45 ` [PATCH v3 30/31] usercopy: Restrict non-usercopy caches to size 0 Kees Cook
2017-09-20 20:45 ` [PATCH v3 31/31] lkdtm: Update usercopy tests for whitelisting Kees Cook

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