| Date | Mon, 12 May 2014 02:34:17 +0200 | From | Willy Tarreau <> | Subject | [ 137/143] xfs: underflow bug in xfs_attrlist_by_handle() |
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2.6.32-longterm review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter <dan.carpenter@oracle.com>
If we allocate less than sizeof(struct attrlist) then we end up corrupting memory or doing a ZERO_PTR_SIZE dereference.
This can only be triggered with CAP_SYS_ADMIN.
Reported-by: Nico Golde <nico@ngolde.de> Reported-by: Fabian Yamaguchi <fabs@goesec.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
(cherry picked from commit 071c529eb672648ee8ca3f90944bcbcc730b4c06) [dannf: backported to Debian's 2.6.32] Signed-off-by: Willy Tarreau <w@1wt.eu> --- fs/xfs/linux-2.6/xfs_ioctl.c | 3 ++- fs/xfs/linux-2.6/xfs_ioctl32.c | 4 ++-- 2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c index 942362f..5663351 100644 --- a/fs/xfs/linux-2.6/xfs_ioctl.c +++ b/fs/xfs/linux-2.6/xfs_ioctl.c @@ -410,7 +410,8 @@ xfs_attrlist_by_handle( return -XFS_ERROR(EPERM); if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t))) return -XFS_ERROR(EFAULT); - if (al_hreq.buflen > XATTR_LIST_MAX) + if (al_hreq.buflen < sizeof(struct attrlist) || + al_hreq.buflen > XATTR_LIST_MAX) return -XFS_ERROR(EINVAL); /* diff --git a/fs/xfs/linux-2.6/xfs_ioctl32.c b/fs/xfs/linux-2.6/xfs_ioctl32.c index bad485a..782d03d 100644 --- a/fs/xfs/linux-2.6/xfs_ioctl32.c +++ b/fs/xfs/linux-2.6/xfs_ioctl32.c @@ -361,8 +361,8 @@ xfs_compat_attrlist_by_handle( if (copy_from_user(&al_hreq, arg, sizeof(compat_xfs_fsop_attrlist_handlereq_t))) return -XFS_ERROR(EFAULT); - if (al_hreq.buflen > XATTR_LIST_MAX) - return -XFS_ERROR(EINVAL); + if (al_hreq.buflen < sizeof(struct attrlist) || + al_hreq.buflen > XATTR_LIST_MAX) /* * Reject flags, only allow namespaces. -- 1.7.12.2.21.g234cd45.dirty
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