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 1B16618C31 for ; Fri, 31 Jan 2025 11:31:38 +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=1738323098; cv=none; b=QmxkUX/U96h8lzi0oXYG0M6SlhALRLl2MDTzmJaQhuI5vdmCc03KCnQAU6Z5BIWPzfK57xMVFFY52mhOVe6r00KKHB73n9X3aCfB8DfzCZN0MBvLSgtlm8kBkoOb5tjq+muOxqtspPYxPgcOeofhQESD/leHGHsssW81x3CfDT8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738323098; c=relaxed/simple; bh=ovZ6OUE9xd2kOv6/M8XttbgSZ7ZsNVlDhi72LZu6MOc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=pT9vcrvAPgtrUSYLzyvwL3gLcP6YVSWAZIoFQqjm86RS7YmIUa2VKQ757drOlSgyH51qYBbm3uLim6vWsdJYCvFeZmOqkYs1Ojh5jlmRPQuWJyGmc6WUFut9LQ01vzUHHIfQ22DdMxNDA0xuHuLDNDcaVude2gNWJ7Q0ZFcXmAc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Aidz3nV0; 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="Aidz3nV0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B8E4C4CED1; Fri, 31 Jan 2025 11:31:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1738323098; bh=ovZ6OUE9xd2kOv6/M8XttbgSZ7ZsNVlDhi72LZu6MOc=; h=From:To:Cc:Subject:Date:Reply-to:From; b=Aidz3nV01K3Koet8ofHaPBVz7xwo1lvT6vaAa2fIGtqrQxmjqITu5dr0EqMMBCwOa o4MKWOZ04gKonFMFkFb+gg1TGvRpKrg+pUCDbsxgMr1yytf8mTLzNwS4vpXSQSE63G zi8rPK7m/W077bLzXWbE7kApl5GBjmsEydxvI4aI= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2025-21682: eth: bnxt: always recalculate features after XDP clearing, fix null-deref Date: Fri, 31 Jan 2025 12:31:14 +0100 Message-ID: <2025013103-CVE-2025-21682-ccfd@gregkh> X-Mailer: git-send-email 2.48.1 Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reply-to: , X-Developer-Signature: v=1; a=openpgp-sha256; l=3730; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=ovZ6OUE9xd2kOv6/M8XttbgSZ7ZsNVlDhi72LZu6MOc=; b=owGbwMvMwCRo6H6F97bub03G02pJDOlztpRznH4s+XwC07aoCbYe7vFzbyR/+Nbwi1cya8k6M 9mL7dXpHbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjCRgosMc6WP8zG4NhrOd2uJ YpMPzFo+a1VzNMOCfUsuFu9If37PMy54c9nU+TmPLk8LBQA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit Description =========== In the Linux kernel, the following vulnerability has been resolved: eth: bnxt: always recalculate features after XDP clearing, fix null-deref Recalculate features when XDP is detached. Before: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: off [requested on] After: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: on The fact that HW-GRO doesn't get re-enabled automatically is just a minor annoyance. The real issue is that the features will randomly come back during another reconfiguration which just happens to invoke netdev_update_features(). The driver doesn't handle reconfiguring two things at a time very robustly. Starting with commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") we only reconfigure the RSS hash table if the "effective" number of Rx rings has changed. If HW-GRO is enabled "effective" number of rings is 2x what user sees. So if we are in the bad state, with HW-GRO re-enablement "pending" after XDP off, and we lower the rings by / 2 - the HW-GRO rings doing 2x and the ethtool -L doing / 2 may cancel each other out, and the: if (old_rx_rings != bp->hw_resc.resv_rx_rings && condition in __bnxt_reserve_rings() will be false. The RSS map won't get updated, and we'll crash with: BUG: kernel NULL pointer dereference, address: 0000000000000168 RIP: 0010:__bnxt_hwrm_vnic_set_rss+0x13a/0x1a0 bnxt_hwrm_vnic_rss_cfg_p5+0x47/0x180 __bnxt_setup_vnic_p5+0x58/0x110 bnxt_init_nic+0xb72/0xf50 __bnxt_open_nic+0x40d/0xab0 bnxt_open_nic+0x2b/0x60 ethtool_set_channels+0x18c/0x1d0 As we try to access a freed ring. The issue is present since XDP support was added, really, but prior to commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") it wasn't causing major issues. The Linux kernel CVE team has assigned CVE-2025-21682 to this issue. Affected and fixed versions =========================== Issue introduced in 4.16 with commit 1054aee82321483dceabbb9b9e5d6512e8fe684b and fixed in 6.12.11 with commit 08831a894d18abfaabb5bbde7c2069a7fb41dd93 Issue introduced in 4.16 with commit 1054aee82321483dceabbb9b9e5d6512e8fe684b and fixed in 6.13 with commit f0aa6a37a3dbb40b272df5fc6db93c114688adcd Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2025-21682 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: drivers/net/ethernet/broadcom/bnxt/bnxt.c drivers/net/ethernet/broadcom/bnxt/bnxt.h drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/08831a894d18abfaabb5bbde7c2069a7fb41dd93 https://git.kernel.org/stable/c/f0aa6a37a3dbb40b272df5fc6db93c114688adcd