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Groups > linux.kernel > #1722563
| From | Kees Cook <keescook@chromium.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 10/30] befs: Define usercopy region in befs_inode_cache slab cache |
| Date | 2017-08-29 17:40 +0200 |
| Message-ID | <ujQMp-4mN-1@gated-at.bofh.it> (permalink) |
| References | <ujzVf-2ie-3@gated-at.bofh.it> <ujzVg-2ie-43@gated-at.bofh.it> <ujLMK-1lA-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Aug 29, 2017 at 3:12 AM, Luis de Bethencourt <luisbg@kernel.org> wrote:
> Hello Kees,
>
> This is great. Thanks :)
>
> Will merge into my befs tree.
Hi! Actually, this depends on the rest of the series, which should be
merged together. If you can Ack this, I'll include it in my usercopy
tree.
Thanks!
-Kees
>
> Luis
>
>
> On 08/28/2017 10:34 PM, Kees Cook wrote:
>>
>> From: David Windsor <dave@nullcore.net>
>>
>> befs symlink pathnames, stored in struct befs_inode_info.i_data.symlink
>> and therefore contained in the befs_inode_cache slab cache, need to be
>> copied to/from userspace.
>>
>> cache object allocation:
>> fs/befs/linuxvfs.c:
>> befs_alloc_inode(...):
>> ...
>> bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
>> ...
>> return &bi->vfs_inode;
>>
>> befs_iget(...):
>> ...
>> strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
>> BEFS_SYMLINK_LEN);
>> ...
>> inode->i_link = befs_ino->i_data.symlink;
>>
>> example usage trace:
>> readlink_copy+0x43/0x70
>> vfs_readlink+0x62/0x110
>> SyS_readlinkat+0x100/0x130
>>
>> fs/namei.c:
>> readlink_copy(..., link):
>> ...
>> copy_to_user(..., link, len);
>>
>> (inlined in vfs_readlink)
>> generic_readlink(dentry, ...):
>> struct inode *inode = d_inode(dentry);
>> const char *link = inode->i_link;
>> ...
>> readlink_copy(..., link);
>>
>> In support of usercopy hardening, this patch defines a region in the
>> befs_inode_cache slab cache in which userspace copy operations are
>> allowed.
>>
>> This region is known as the slab cache's usercopy region. Slab caches can
>> now check that each copy operation involving cache-managed memory falls
>> entirely within the slab's usercopy region.
>>
>> This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY
>> whitelisting code in the last public patch of grsecurity/PaX based on my
>> understanding of the code. Changes or omissions from the original code are
>> mine and don't reflect the original grsecurity/PaX code.
>>
>> Signed-off-by: David Windsor <dave@nullcore.net>
>> [kees: adjust commit log, provide usage trace]
>> Cc: Luis de Bethencourt <luisbg@kernel.org>
>> Cc: Salah Triki <salah.triki@gmail.com>
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>> ---
>> fs/befs/linuxvfs.c | 14 +++++++++-----
>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
>> index 4a4a5a366158..1c2dcbee79dd 100644
>> --- a/fs/befs/linuxvfs.c
>> +++ b/fs/befs/linuxvfs.c
>> @@ -444,11 +444,15 @@ static struct inode *befs_iget(struct super_block
>> *sb, unsigned long ino)
>> static int __init
>> befs_init_inodecache(void)
>> {
>> - befs_inode_cachep = kmem_cache_create("befs_inode_cache",
>> - sizeof (struct
>> befs_inode_info),
>> - 0, (SLAB_RECLAIM_ACCOUNT|
>> -
>> SLAB_MEM_SPREAD|SLAB_ACCOUNT),
>> - init_once);
>> + befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache",
>> + sizeof(struct befs_inode_info), 0,
>> + (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
>> + SLAB_ACCOUNT),
>> + offsetof(struct befs_inode_info,
>> + i_data.symlink),
>> + sizeof_field(struct befs_inode_info,
>> + i_data.symlink),
>> + init_once);
>> if (befs_inode_cachep == NULL)
>> return -ENOMEM;
>>
>
>
--
Kees Cook
Pixel Security
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v2 00/30] Hardened usercopy whitelisting Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 07/30] ext4: Define usercopy region in ext4_inode_cache slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 09/30] jfs: Define usercopy region in jfs_ip slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 06/30] vfs: Copy struct mount.mnt_id to userspace using put_user() Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 05/30] vfs: Define usercopy region in names_cache slab caches Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 08/30] ext2: Define usercopy region in ext2_inode_cache slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
Re: [PATCH v2 08/30] ext2: Define usercopy region in ext2_inode_cache slab cache Jan Kara <jack@suse.cz> - 2017-08-30 13:30 +0200
[PATCH v2 13/30] ufs: Define usercopy region in ufs_inode_cache slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 16/30] cifs: Define usercopy region in cifs_request slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 02/30] usercopy: Enforce slab cache usercopy region boundaries Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 20/30] caif: Define usercopy region in caif proto slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 01/30] usercopy: Prepare for usercopy whitelisting Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 11/30] exofs: Define usercopy region in exofs_inode_cache slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 04/30] dcache: Define usercopy region in dentry_cache slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
[PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Kees Cook <keescook@chromium.org> - 2017-08-29 00:00 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-08-29 06:50 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Kees Cook <keescook@chromium.org> - 2017-08-29 20:50 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-08-29 21:10 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Dave Chinner <david@fromorbit.com> - 2017-08-30 00:20 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Kees Cook <keescook@chromium.org> - 2017-08-30 00:30 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-08-29 00:00 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Christoph Hellwig <hch@infradead.org> - 2017-08-29 10:20 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Dave Chinner <david@fromorbit.com> - 2017-08-29 14:40 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Christoph Hellwig <hch@infradead.org> - 2017-08-29 14:50 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Dave Chinner <david@fromorbit.com> - 2017-08-30 00:00 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Christoph Hellwig <hch@infradead.org> - 2017-08-30 09:20 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Dave Chinner <david@fromorbit.com> - 2017-08-30 10:10 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Christoph Hellwig <hch@infradead.org> - 2017-08-30 10:40 +0200
Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache Kees Cook <keescook@chromium.org> - 2017-08-29 21:00 +0200
[PATCH v2 10/30] befs: Define usercopy region in befs_inode_cache slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:40 +0200
Re: [PATCH v2 10/30] befs: Define usercopy region in befs_inode_cache slab cache Luis de Bethencourt <luisbg@kernel.org> - 2017-08-29 12:20 +0200
Re: [PATCH v2 10/30] befs: Define usercopy region in befs_inode_cache slab cache Kees Cook <keescook@chromium.org> - 2017-08-29 17:40 +0200
Re: [PATCH v2 10/30] befs: Define usercopy region in befs_inode_cache slab cache Luis de Bethencourt <luisbg@kernel.org> - 2017-08-29 19:20 +0200
[PATCH v2 25/30] fork: Define usercopy region in thread_stack slab caches Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
Re: [kernel-hardening] [PATCH v2 25/30] fork: Define usercopy region in thread_stack slab caches Rik van Riel <riel@redhat.com> - 2017-08-30 21:00 +0200
[PATCH v2 21/30] sctp: Define usercopy region in SCTP proto slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
[PATCH v2 19/30] ip: Define usercopy region in IP proto slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
[PATCH v2 22/30] sctp: Copy struct sctp_sock.autoclose to userspace using put_user() Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
[PATCH v2 29/30] arm: Implement thread_struct whitelist for hardened usercopy Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
[PATCH v2 30/30] usercopy: Restrict non-usercopy caches to size 0 Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
[PATCH v2 14/30] vxfs: Define usercopy region in vxfs_inode slab cache Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
[PATCH v2 24/30] fork: Define usercopy region in mm_struct slab caches Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
Re: [kernel-hardening] [PATCH v2 24/30] fork: Define usercopy region in mm_struct slab caches Rik van Riel <riel@redhat.com> - 2017-08-30 21:30 +0200
[PATCH v2 23/30] net: Restrict unwhitelisted proto caches to size 0 Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
[PATCH v2 26/30] fork: Provide usercopy whitelisting for task_struct Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
Re: [kernel-hardening] [PATCH v2 26/30] fork: Provide usercopy whitelisting for task_struct Rik van Riel <riel@redhat.com> - 2017-08-30 21:00 +0200
[PATCH v2 28/30] arm64: Implement thread_struct whitelist for hardened usercopy Kees Cook <keescook@chromium.org> - 2017-08-28 23:50 +0200
[PATCH v2 27/30] x86: Implement thread_struct whitelist for hardened usercopy Kees Cook <keescook@chromium.org> - 2017-08-29 00:00 +0200
Re: [kernel-hardening] [PATCH v2 27/30] x86: Implement thread_struct whitelist for hardened usercopy Rik van Riel <riel@redhat.com> - 2017-08-30 21:00 +0200
[PATCH v2 18/30] net: Define usercopy region in struct proto slab cache Kees Cook <keescook@chromium.org> - 2017-08-29 00:00 +0200
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