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 4823E314B7C; Wed, 3 Dec 2025 15:48:41 +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=1764776921; cv=none; b=NNcl38/E8KK6GtuIFjk3sWMS3MhVKS+T45TOLieCzpxwgaBVkRDK6jj/bYDWRAOYerebasJUGs1E2eSId2OXfkPAihspKSq67MvIEAlp6joO2RkMy9zenVysiWv7HBw3inf/9tI8Bhd//bFA4933eTPicsjCNCalB/g3YYurf/g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764776921; c=relaxed/simple; bh=Jg2t8fWCelmUYRKrXDN49NfJWac2v8L1Be2NjY8xLV0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u1qft2EZV5BMeaB4p9SwTocJt5e2KJoKfztOY1ALVi/XRZmNQGOShP0i0hDx/0CulUaHUN3mSpno+5PzBEkmpI7cEB3JKY0UcqM6XhsQYchkqs2UDNwrMExpegS1K2THkmngs281koZQcssTYpX0iCBaQ9Xfcv1i3Ju6Lu1IqMY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=uBQ4QlmN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="uBQ4QlmN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6ABD5C4CEF5; Wed, 3 Dec 2025 15:48:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764776920; bh=Jg2t8fWCelmUYRKrXDN49NfJWac2v8L1Be2NjY8xLV0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uBQ4QlmNUccVZci61rw0kn1HIslGxvQK7Qd52JKTdC7qfALuQrTvop0hUk8n1idNB /K5REGNzkDTpfVFnbZ9b4GTs8CFfZhkb770sxtOJ9J77f2KMmLeReInBQWXq3wt95E 6Oj9cgV0WtEfV1paQu4Z49Eu6Anfkx3GQ6AkJIk0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mohsin Bashir , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.17 027/146] eth: fbnic: Fix counter roll-over issue Date: Wed, 3 Dec 2025 16:26:45 +0100 Message-ID: <20251203152347.462053636@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152346.456176474@linuxfoundation.org> References: <20251203152346.456176474@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mohsin Bashir [ Upstream commit 6d66e093e0740d39a36ef742c60eec247df26f41 ] Fix a potential counter roll-over issue in fbnic_mbx_alloc_rx_msgs() when calculating descriptor slots. The issue occurs when head - tail results in a large positive value (unsigned) and the compiler interprets head - tail - 1 as a signed value. Since FBNIC_IPC_MBX_DESC_LEN is a power of two, use a masking operation, which is a common way of avoiding this problem when dealing with these sort of ring space calculations. Fixes: da3cde08209e ("eth: fbnic: Add FW communication mechanism") Signed-off-by: Mohsin Bashir Link: https://patch.msgid.link/20251125211704.3222413-1-mohsin.bashr@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/meta/fbnic/fbnic_fw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c index 0c55be7d25476..acc1ad91b0c3a 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c @@ -201,7 +201,7 @@ static int fbnic_mbx_alloc_rx_msgs(struct fbnic_dev *fbd) return -ENODEV; /* Fill all but 1 unused descriptors in the Rx queue. */ - count = (head - tail - 1) % FBNIC_IPC_MBX_DESC_LEN; + count = (head - tail - 1) & (FBNIC_IPC_MBX_DESC_LEN - 1); while (!err && count--) { struct fbnic_tlv_msg *msg; -- 2.51.0