Re: [PATCH 190/190] Revert "ethtool: fix a potential missing-check bug"

James Morris
2021-04-21T20:10:52Z

On Wed, 21 Apr 2021, Greg Kroah-Hartman wrote:

> This reverts commit d656fe49e33df48ee6bc19e871f5862f49895c9e.
>
> Commits from @umn.edu addresses have been found to be submitted in "bad
> faith" to try to test the kernel community's ability to review "known
> malicious" changes. The result of these submissions can be found in a
> paper published at the 42nd IEEE Symposium on Security and Privacy
> entitled, "Open Source Insecurity: Stealthily Introducing
> Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> of Minnesota) and Kangjie Lu (University of Minnesota).
>
> Because of this, all submissions from this group must be reverted from
> the kernel tree and will need to be re-reviewed again to determine if
> they actually are a valid fix. Until that work is complete, remove this
> change to ensure that no problems are being introduced into the
> codebase.
>
> Cc: Wenwen Wang <wang6495@umn.edu>
> Cc: David S. Miller <davem@davemloft.net>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The original patch looks valid and fixes a race.

Reviewed-by: James Morris <jamorris@linux.microsoft.com>

> ---
> net/ethtool/ioctl.c | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
> index 807bc9465add..542f2428014c 100644
> --- a/net/ethtool/ioctl.c
> +++ b/net/ethtool/ioctl.c
> @@ -869,11 +869,6 @@ static noinline_for_stack int ethtool_get_rxnfc(struct net_device *dev,
> info_size = sizeof(info);
> if (copy_from_user(&info, useraddr, info_size))
> return -EFAULT;
> - /* Since malicious users may modify the original data,
> - * we need to check whether FLOW_RSS is still requested.
> - */
> - if (!(info.flow_type & FLOW_RSS))
> - return -EINVAL;
> }
>
> if (info.cmd == ETHTOOL_GRXCLSRLALL) {
> --
> 2.31.1
>

--
James Morris
<jmorris@namei.org>