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Sun, 04 Oct 2026 21:38:19 -0700 (PDT) From: Abdul Wasey To: netdev-bot+sashiko@kernel.org Cc: netdev@vger.kernel.org, razor@blackwall.org, idosch@nvidia.com, davem@davemloft.net, edumazet@kernel.org, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, horatiu.vultur@microchip.com, bridge@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next] net: bridge: cfm: notify userspace on CFM config changes Date: Mon, 5 Oct 2026 04:38:12 +0000 Message-ID: <20261005043812.3106517-1-w453y.me@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <179117378916.434549.16185635728868721491@kernel.org> References: <179117378916.434549.16185635728868721491@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Mon, 05 Oct 2026 04:16:29 +0000, netdev-bot+sashiko@kernel.org wrote: > [Severity: High] > Is the skb that br_info_notify() allocates large enough for a message > with only RTEXT_FILTER_CFM_CONFIG set? Right, this is a real bug. br_get_link_af_size_filtered() never counts the config attributes, so the notification only fit for small configs. I reproduced it: with one MEP and about 32 peer MEPs every config change hits the WARN_ON in br_info_notify() and the notification is lost. v2 adds a patch before this one that counts the config attributes when RTEXT_FILTER_CFM_CONFIG is set. > [Severity: Medium] > What does userspace receive when this request deletes the last MEP? Right, it gets an RTM_NEWLINK with no IFLA_BRIDGE_CFM at all, which can't be told apart from other bridge notifications. v2 sends an empty IFLA_BRIDGE_CFM nest for a bridge with no MEPs, so that case is visible. pw-bot: cr