From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7836330D35; Tue, 31 Mar 2026 01:15:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774919743; cv=none; b=f7jCc6v549k/dNxiQIcyz9dNivPy02J1pSAHJih2VDjfJtM31R/UH0wWK8E3nZiQNbGxexL7q6CbCXH2C2YBuCtHKHdKsBN9wpuxEpdhwrlY5QeJd4prp3u/tgbecLeUftjV/3237cAjPO3Pn36/o2SgCpSZGcW5Lgb+eB3QB4A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774919743; c=relaxed/simple; bh=UBaPmHil6IXzTPcGISlvOCZ/I22GqdHJcpvM+detDE8=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZoJ/9saY9eve3vnlKM8/GhjtLvZ4ND2ZocgtEArV2ndopUN4GzYK3buSvh+qVJtjbLRBEvtbKltqZ8Kad/voNI31TDDhT3Q9GgNOvqCqUaZeUG47xWBlYNz0wZ/ZI3dQhlYp4j/GjBa0njdL9e0YDZPXdMn9tZGBInzYpzuriIo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SGFqBAq1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SGFqBAq1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D50D2C4CEF7; Tue, 31 Mar 2026 01:15:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774919742; bh=UBaPmHil6IXzTPcGISlvOCZ/I22GqdHJcpvM+detDE8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=SGFqBAq1gLiql5UYZ9Thr89MaqQPfSieEyrRByzEnmw6W+UlRkoRuYXeAWU5f20VC RK5GTMSeEJWqFA8QQlXDFYZPWnLx8byWoqB0TKBB9kEEMFWr5Qsm0FEHThKMEnWhwf Vrja5eqoS+ixLOqethGSfQN/E1D+IJmizzqGQvNU5ugeT/ZOkyIp/HyhRLY3MVKxgi LPpZsCuFtMG2tCO++trNyTdDRKwOrTStV60XIzLCxjDQGQCVDG+DbBgRg0FgJZwCMf 8dcFC2hcoT/blb1ciC0UcEjA85CyGgFUR/AaTvz8lIrFJZYVxGbZprsnLqhcRsasP8 xAyfh9brUonWQ== Date: Mon, 30 Mar 2026 18:15:41 -0700 From: Jakub Kicinski To: Kangzheng Gu Cc: gregkh@linuxfoundation.org, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, horms@kernel.org, kees@kernel.org, p@1g4.org, netdev@vger.kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net-shapers: free rollback entries using kfree_rcu Message-ID: <20260330181541.5a3c9f73@kernel.org> In-Reply-To: <20260328185804.41325-1-xiaoguai0992@gmail.com> References: <20260328185804.41325-1-xiaoguai0992@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 28 Mar 2026 18:58:04 +0000 Kangzheng Gu wrote: > net_shaper_rollback() removes NET_SHAPER_NOT_VALID entries and frees > them using kfree(), which can race with net_shaper_nl_get_dumpit() and > lead to a use-after-free in net_shaper_fill_one(). > > Use kfree_rcu() instead of kfree() to free rollback entries, since > net_shaper_nl_get_dumpit() protects shaper access with rcu_read_lock(). If dump can see NOT_VALID entries we have a bigger problem than a UAF don't you think? :/