From: Leon Romanovsky <leon@kernel.org>
To: Zhou Qingyang <zhou1615@umn.edu>
Cc: kjlu@umn.edu, Tariq Toukan <tariqt@nvidia.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Eugenia Emantayev <eugenia@mellanox.com>,
netdev@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net/mlx4_en: Fix an use-after-free bug in mlx4_en_try_alloc_resources()
Date: Wed, 1 Dec 2021 11:27:43 +0200 [thread overview]
Message-ID: <YadAD+x2C9ZHh03e@unreal> (raw)
In-Reply-To: <20211130164438.190591-1-zhou1615@umn.edu>
On Wed, Dec 01, 2021 at 12:44:38AM +0800, Zhou Qingyang wrote:
> In mlx4_en_try_alloc_resources(), mlx4_en_copy_priv() is called and
> tmp->tx_cq will be freed on the error path of mlx4_en_copy_priv().
> After that mlx4_en_alloc_resources() is called and there is a dereference
> of &tmp->tx_cq[t][i] in mlx4_en_alloc_resources(), which could lead to
> a use after free problem on failure of mlx4_en_copy_priv().
>
> Fix this bug by adding a check of mlx4_en_copy_priv()
>
> This bug was found by a static analyzer. The analysis employs
> differential checking to identify inconsistent security operations
> (e.g., checks or kfrees) between two code paths and confirms that the
> inconsistent operations are not recovered in the current function or
> the callers, so they constitute bugs.
>
> Note that, as a bug found by static analysis, it can be a false
> positive or hard to trigger. Multiple researchers have cross-reviewed
> the bug.
>
> Builds with CONFIG_MLX4_EN=m show no new warnings,
> and our static analyzer no longer warns about this code.
>
> Fixes: ec25bc04ed8e ("net/mlx4_en: Add resilience in low memory systems")
> Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
> ---
> drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
next prev parent reply other threads:[~2021-12-01 9:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 16:44 [PATCH] net/mlx4_en: Fix an use-after-free bug in mlx4_en_try_alloc_resources() Zhou Qingyang
2021-12-01 9:27 ` Leon Romanovsky [this message]
2021-12-02 3:10 ` patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YadAD+x2C9ZHh03e@unreal \
--to=leon@kernel.org \
--cc=davem@davemloft.net \
--cc=eugenia@mellanox.com \
--cc=kjlu@umn.edu \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=tariqt@nvidia.com \
--cc=zhou1615@umn.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).