From patchwork Mon Jan 20 11:53:53 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Denis Arefev X-Patchwork-Id: 13945033 X-Patchwork-Delegate: kuba@kernel.org Received: from mx.swemel.ru (mx.swemel.ru [95.143.211.150]) (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 8E02E18FDC8; Mon, 20 Jan 2025 11:53:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.143.211.150 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737374040; cv=none; b=b10PdnXcQGMbDP/t2QhqLjOjokH5HCVl88/ckAHx7JJY8fWzi1fZRN0Jjs31ylGRht3M5wkmjMrqrwENET4sphNnv6dNvqYcxjyMvPWvpEcRMHzDsQHwzD+O2f02DdWYRmkr143eaPZGhTqesU2pMUGJBjVtUEfQuPKfWNQadk8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737374040; c=relaxed/simple; bh=ckmUieoQ6c7b2h5qvdikaklIDj7v6vTDGluUVK1/L88=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=grziisnd40EC5/OYo3p99T2a4s8vm78d+r7v4BGkWL3ZznDqTeWVZRUMudddUo/wQXTSGZt7RLnHMIDTo+V8wkTBJFPCHIaT/aiX6tbru46KNIOPdUYYNRV+8GAdzDhfmI3EEJKhVjjOLnAW4D3mpSZa/Vj/WoCm2s2PL3noxwc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=swemel.ru; spf=pass smtp.mailfrom=swemel.ru; dkim=pass (1024-bit key) header.d=swemel.ru header.i=@swemel.ru header.b=jqOCzB7p; arc=none smtp.client-ip=95.143.211.150 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=swemel.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=swemel.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=swemel.ru header.i=@swemel.ru header.b="jqOCzB7p" From: Denis Arefev DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=swemel.ru; s=mail; t=1737374034; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=mXZ3I+8rEu5hC7Bbr/07M4uZY5uMU2tu8N9VtF7I1iA=; b=jqOCzB7pFmmic5jfsD/stli7oRpav9Pv1HpqWYAbYMGjlBbhNW/x4/xgl1Ne942/izqIzb KsLDTvokPyL03Z9hXWk12SPJlnJeCnKfyYnAmUWYjxkPwn5rNYj+9NyLQSqvy1wZtgkVSs vqRoDwi8z3B4ygD7q98J9L/5cIQ9lEc= To: stable@vger.kernel.org, Greg Kroah-Hartman Cc: Nick Child , Dany Madden , Lijun Pan , Sukadev Bhattiprolu , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Paolo Abeni Subject: [PATCH] ibmvnic: Add tx check to prevent skb leak Date: Mon, 20 Jan 2025 14:53:53 +0300 Message-ID: <20250120115354.49654-1-arefev@swemel.ru> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Nick Child From: Nick Child commit 0983d288caf984de0202c66641577b739caad561 upstream. Below is a summary of how the driver stores a reference to an skb during transmit: tx_buff[free_map[consumer_index]]->skb = new_skb; free_map[consumer_index] = IBMVNIC_INVALID_MAP; consumer_index ++; Where variable data looks like this: free_map == [4, IBMVNIC_INVALID_MAP, IBMVNIC_INVALID_MAP, 0, 3] consumer_index^ tx_buff == [skb=null, skb=, skb=, skb=null, skb=null] The driver has checks to ensure that free_map[consumer_index] pointed to a valid index but there was no check to ensure that this index pointed to an unused/null skb address. So, if, by some chance, our free_map and tx_buff lists become out of sync then we were previously risking an skb memory leak. This could then cause tcp congestion control to stop sending packets, eventually leading to ETIMEDOUT. Therefore, add a conditional to ensure that the skb address is null. If not then warn the user (because this is still a bug that should be patched) and free the old pointer to prevent memleak/tcp problems. Signed-off-by: Nick Child Signed-off-by: Paolo Abeni [Denis: minor fix to resolve merge conflict.] Signed-off-by: Denis Arefev --- Backport fix for CVE-2024-41066 Link: https://nvd.nist.gov/vuln/detail/CVE-2024-41066 --- drivers/net/ethernet/ibm/ibmvnic.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 84da6ccaf339..439796975cbf 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -1625,6 +1625,18 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) (tx_pool->consumer_index + 1) % tx_pool->num_buffers; tx_buff = &tx_pool->tx_buff[index]; + + /* Sanity checks on our free map to make sure it points to an index + * that is not being occupied by another skb. If skb memory is + * not freed then we see congestion control kick in and halt tx. + */ + if (unlikely(tx_buff->skb)) { + dev_warn_ratelimited(dev, "TX free map points to untracked skb (%s %d idx=%d)\n", + skb_is_gso(skb) ? "tso_pool" : "tx_pool", + queue_num, bufidx); + dev_kfree_skb_any(tx_buff->skb); + } + tx_buff->skb = skb; tx_buff->data_dma[0] = data_dma_addr; tx_buff->data_len[0] = skb->len;