Commit 31978b5c authored by Dan Carpenter's avatar Dan Carpenter Committed by Ben Myers

xfs: underflow bug in xfs_attrlist_by_handle()

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: default avatarNico Golde <nico@ngolde.de>
Reported-by: default avatarFabian Yamaguchi <fabs@goesec.de>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarBen Myers <bpm@sgi.com>

(cherry picked from commit 071c529e)
parent dc1ccc48
......@@ -442,7 +442,8 @@ 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);
/*
......
......@@ -356,7 +356,8 @@ 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)
if (al_hreq.buflen < sizeof(struct attrlist) ||
al_hreq.buflen > XATTR_LIST_MAX)
return -XFS_ERROR(EINVAL);
/*
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment