Re: [Qemu-devel] [PATCH v2 11/28] 9pfs: local: unlinkat: don't follow symlinks

[Stefan Hajnoczi]

On Sun, Feb 26, 2017 at 11:43:00PM +0100, Greg Kurz wrote:
> The local_unlinkat() callback is vulnerable to symlink attacks because it
> calls remove() which follows symbolic links in all path elements but the
> rightmost one.
> 
> This patch converts local_unlinkat() to rely on opendir_nofollow() and
> unlinkat() instead.
> 
> Most of the code is moved to a separate local_unlinkat_common() helper
> which will be reused in a subsequent patch to fix the same issue in
> local_remove().
> 
> This partly fixes CVE-2016-9602.
> 
> Signed-off-by: Greg Kurz <address@hidden>
> Reviewed-by: Stefan Hajnoczi <address@hidden>
> ---
> v2: - use openat_dir()
> ---
>  hw/9pfs/9p-local.c |   99 
> +++++++++++++++++++++++++++++-----------------------
>  1 file changed, 56 insertions(+), 43 deletions(-)

Reviewed-by: Stefan Hajnoczi <address@hidden>

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