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 4215B45BE3; Fri, 6 Sep 2024 08:30:42 +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=1725611443; cv=none; b=DCmxxZlA3C8kO5+qEOY2yPLJQwNI52T+xN3O6vHI+Y70MKxWt7+P0WjCWoarlp0XZz7QtgwXfXOBWK0JsRblEsBOZUOSQbksgVNGtCg/oOmx0zY1m1UUG0+gQX1aeT4rv+nHgRwNxE9mLCL+MbBLNAG7CSdnl7zX+gnqx9dWF3k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725611443; c=relaxed/simple; bh=A5dq9VXSOyYLnbKAephiLb4/q2ZPRZWcqiBaCOExek4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FVSXLKdkEmvibqVl4I/k2lI10WW5jlrpuioRs5TzIT0Bi1RI4v7jZcmkPi8D/TQ5iR3kC52ZtY/OE+9RTS6W4td4RmZDwLv6tN/q1nj4JP5wRtqiWdrKNnowyu6nVH73kuftEMYBROa6g82AVuzex9y2TSrJ+K1aBMtY9CEjzZk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SWv0+dmp; 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="SWv0+dmp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 619BBC4CEC4; Fri, 6 Sep 2024 08:30:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725611442; bh=A5dq9VXSOyYLnbKAephiLb4/q2ZPRZWcqiBaCOExek4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SWv0+dmp0VjjpwgOjn/rgchbdug4Cxd8CeXi17mh1b0caKbFg21RCbpO1xdkdEA3+ UymzcCa7gSnv4pDx4yzQTEuwr2Jz/z58ImXpGaDYfed7FPRb4CaAt1b/4gFuZP9Y8c 9EZf8pTXk6Ycd3KP+Vi4IDTRUNB2QcuS8RU6dy8JBVho43tpxE0T3sRwSn67l1Actk 6lIZoXB/cJJrtaigyAABRHFX9913ntCZJR2iHERmKaCl7C+mPy8r8izFNlYviDJpAZ q8aXYWL6HPNNRKB9ZtzJhIhYM3DmAfDbVAioCltQU9AwdksKpsW7nMfewX8PLvb+dH LZG4fbO9qdUzw== Date: Fri, 6 Sep 2024 09:30:38 +0100 From: Simon Horman To: Gui-Dong Han Cc: anthony.l.nguyen@intel.com, przemyslaw.kitszel@intel.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, baijiaju1990@gmail.com, stable@vger.kernel.org Subject: Re: [PATCH v2] ice: Fix improper handling of refcount in ice_sriov_set_msix_vec_count() Message-ID: <20240906083038.GC2097826@kernel.org> References: 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-Disposition: inline In-Reply-To: On Tue, Sep 03, 2024 at 11:59:43AM +0000, Gui-Dong Han wrote: > This patch addresses an issue with improper reference count handling in the > ice_sriov_set_msix_vec_count() function. > > First, the function calls ice_get_vf_by_id(), which increments the > reference count of the vf pointer. If the subsequent call to > ice_get_vf_vsi() fails, the function currently returns an error without > decrementing the reference count of the vf pointer, leading to a reference > count leak. The correct behavior, as implemented in this patch, is to > decrement the reference count using ice_put_vf(vf) before returning an > error when vsi is NULL. > > Second, the function calls ice_sriov_get_irqs(), which sets > vf->first_vector_idx. If this call returns a negative value, indicating an > error, the function returns an error without decrementing the reference > count of the vf pointer, resulting in another reference count leak. The > patch addresses this by adding a call to ice_put_vf(vf) before returning > an error when vf->first_vector_idx < 0. > > This bug was identified by an experimental static analysis tool developed > by our team. The tool specializes in analyzing reference count operations > and identifying potential mismanagement of reference counts. In this case, > the tool flagged the missing decrement operation as a potential issue, > leading to this patch. > > Fixes: 4035c72dc1ba ("ice: reconfig host after changing MSI-X on VF") > Fixes: 4d38cb44bd32 ("ice: manage VFs MSI-X using resource tracking") > Cc: stable@vger.kernel.org > Signed-off-by: Gui-Dong Han > --- > v2: > * In this patch v2, an additional resource leak was addressed when > vf->first_vector_idx < 0. The issue is now fixed by adding ice_put_vf(vf) > before returning an error. > Thanks to Simon Horman for identifying this additional leak scenario. Thanks for the update, I agree with the analysis and that the two instances of this problem were introduced by each of the cited commits. Reviewed-by: Simon Horman