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Groups > linux.kernel > #1722300
| From | Luis de Bethencourt <luisbg@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 10/30] befs: Define usercopy region in befs_inode_cache slab cache |
| Date | 2017-08-29 12:20 +0200 |
| Message-ID | <ujLMK-1lA-9@gated-at.bofh.it> (permalink) |
| References | <ujzVf-2ie-3@gated-at.bofh.it> <ujzVg-2ie-43@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Hello Kees,
This is great. Thanks :)
Will merge into my befs tree.
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;
>
>
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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