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Date:   Thu, 26 Oct 2023 16:00:00 -0700
From:   Saeed Mahameed <saeed@kernel.org>
To:     Dust Li <dust.li@linux.alibaba.com>
Cc:     Saeed Mahameed <saeedm@nvidia.com>,
        Leon Romanovsky <leon@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
        Cruz Zhao <cruzzhao@linux.alibaba.com>,
        Tianchen Ding <dtcccc@linux.alibaba.com>
Subject: Re: [PATCH net] net/mlx5e: fix double free of encap_header
Message-ID: <ZTrvcHEC/rU1G4ct@x130>
References: <20231025032712.79026-1-dust.li@linux.alibaba.com>
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In-Reply-To: <20231025032712.79026-1-dust.li@linux.alibaba.com>
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On 25 Oct 11:27, Dust Li wrote:
>When mlx5_packet_reformat_alloc() fails, the encap_header allocated in
>mlx5e_tc_tun_create_header_ipv4{6} will be released within it. However,
>e->encap_header is already set to the previously freed encap_header
>before mlx5_packet_reformat_alloc(). As a result, the later
>mlx5e_encap_put() will free e->encap_header again, causing a double free
>issue.
>
>mlx5e_encap_put()
>    --> mlx5e_encap_dealloc()
>        --> kfree(e->encap_header)
>
>This happens when cmd: MLX5_CMD_OP_ALLOC_PACKET_REFORMAT_CONTEXT fail.
>
>This patch fix it by not setting e->encap_header until
>mlx5_packet_reformat_alloc() success.
>
>Fixes: d589e785baf5e("net/mlx5e: Allow concurrent creation of encap entries")
>Reported-by: Cruz Zhao <cruzzhao@linux.alibaba.com>
>Reported-by: Tianchen Ding <dtcccc@linux.alibaba.com>
>Signed-off-by: Dust Li <dust.li@linux.alibaba.com>

Applied to net-mlx5