From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f43.google.com (mail-dl1-f43.google.com [74.125.82.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5EAFE3DDDDE for ; Wed, 18 Mar 2026 15:03:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773846193; cv=none; b=NxF2cvxzTpB+ttFYtA2LuT9esIT4i3rpCCtiMcOmuy05J1re3+KK2vADxBHQRWniKVtEXAHsGCOfNI0k5zHmRBRXiFBFy88xFE6wUJORN85RbiYIiWiVHJ6E7AMrCt9BsWphew8267BOHA1yuhEAhSUG2dv/2JYd4hAy4evWnfo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773846193; c=relaxed/simple; bh=h0p10z8eZpClUXYtUVukCJgrHGYSRkh1nSA6pgFkCig=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZxIfpjsrZokGbnZC+cgUntjSohZzc1Ah5GbflyroSAJ65sbFAXqYkUPzcG4zA1NZvV14+V3iIi8PbwcnJrD1y0lf1cMvklyzYYMZbItCV1h5zkP7qPT+A8oUjFURQ9Uh4Y+gLeqy3otlcPa8Hx/Ia+dk4ffSMmvO/lxl9hhyKVE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=74.125.82.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-dl1-f43.google.com with SMTP id a92af1059eb24-127380532eeso191854c88.1 for ; Wed, 18 Mar 2026 08:03:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1773846190; x=1774450990; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=bCbPYXsJyjrslfVQf+TqWui1no/uksX6ojvJaHIhI9s=; b=AMKelMs2GQ7tH9LmGlmVkMrCYNg1DQJf8Kn6jqwUPa2/dJq/2kDX5nkvhs5BltnTap 1i2wVED4V/Xd/ELdB/G6yt1Xp+Bkpfp24nVw9k8sJlT7m48ie7J5T/stv2Zj7VGl0a2H ap9GTFYbFDBbIKq3QGrWV4KTjHxvJfW8M6hAySMN18WyVjGgdUZZPTXpQRNuDoXlv26t D67S2/+6TysLzpdDngSO2xICNL+ehgIGMgyK0mp1GHBnRVReYJg931y+wlFw8yNSr+gR lF2qG9ZblrzTayh0cCGpvm3VxX5uQCyiP2cRtK9OUnNzUII2h7JgsKujNIXkhuDpblBV TLwQ== X-Gm-Message-State: AOJu0Yzlv5g8t+u8/7t1BYvzBxiOu+ajIRYRN6X8jjKqRUr74j+B+Glc JayqJ0HAMyPx6LAfpEt/Wg0OS9sDpIgkuOmPRPAWycXBWdfg6dflCyHgUmHi X-Gm-Gg: ATEYQzzZQ6e4qJIt3RSpbogOxPm1zOmcB1+KuYJcUe3aNI+LKJDjhR/am5l8kEYKcoa x6AHMq7ydSjJg/HX4ikToDOA0AIwo9Q+v6GfEeWcghS+o8DKCRdFilrfiHqyYOhzsGlM8ocK4vO oDivKj7ZQCQgmTwFWo3BwYCToRkhMlPMCijPL9/o7N+2xupSzSuYVMwOAQTUB3DoqiYvpn8eHuQ HQ33enxKmLoATfmevkkiec455MxZ/ukxdzdwzhC81nTSsT8GQlCXvRokk/GJ7jMkTjrAWAhxPPj 70VjRwg2Gzg0IMWqLQCMq5FZBmC5k88AeNDgJHyp0f/2nPDpvV6Hn71QVFu6tq7Ql+6sMptbNfc 0xzNc+XQR6ksJojF44oXyf2nJ1rMBSxKWsR/Isv92pMTTwkKRxrnDq77ur7vYOYIA6O1883hTyW mFyyg6sce+aVayCEB5YE4myy48v/AEKI0fp3sSwev0EYhcxaSe2tJZ0nMjYeT/flAk2fX0MJatA 3UDIVgG7hP9BKpdfA== X-Received: by 2002:a05:7022:6a5:b0:122:153:d161 with SMTP id a92af1059eb24-1299ba3e35fmr1920293c88.17.1773846189957; Wed, 18 Mar 2026 08:03:09 -0700 (PDT) Received: from localhost (c-76-102-12-149.hsd1.ca.comcast.net. [76.102.12.149]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-129b413930esm3529158c88.13.2026.03.18.08.03.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Mar 2026 08:03:09 -0700 (PDT) From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, corbet@lwn.net, skhan@linuxfoundation.org, andrew+netdev@lunn.ch, michael.chan@broadcom.com, pavan.chebbi@broadcom.com, anthony.l.nguyen@intel.com, przemyslaw.kitszel@intel.com, saeedm@nvidia.com, tariqt@nvidia.com, mbloch@nvidia.com, alexanderduyck@fb.com, kernel-team@meta.com, johannes@sipsolutions.net, sd@queasysnail.net, jianbol@nvidia.com, dtatulea@nvidia.com, sdf@fomichev.me, mohsin.bashr@gmail.com, jacob.e.keller@intel.com, willemb@google.com, skhawaja@google.com, bestswngs@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, linux-rdma@vger.kernel.org, linux-wireless@vger.kernel.org, linux-kselftest@vger.kernel.org, leon@kernel.org Subject: [PATCH net-next v2 02/13] wifi: cfg80211: use __rtnl_unlock in nl80211_pre_doit Date: Wed, 18 Mar 2026 08:02:54 -0700 Message-ID: <20260318150305.123900-3-sdf@fomichev.me> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260318150305.123900-1-sdf@fomichev.me> References: <20260318150305.123900-1-sdf@fomichev.me> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit nl80211_pre_doit acquires rtnl_lock and then wiphy_lock, releasing rtnl while keeping wiphy_lock held until post_doit. With the introduction of rx_mode_wq and its flush in netdev_run_todo, calling rtnl_unlock here creates a circular lock dependency: Chain exists of: (wq_completion)rx_mode_wq --> rtnl_mutex --> &rdev->wiphy.mtx Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rdev->wiphy.mtx); lock(rtnl_mutex); lock(&rdev->wiphy.mtx); lock((wq_completion)rx_mode_wq); Switch to __rtnl_unlock to skip netdev_run_todo in nl80211_pre_doit. This seems safe because we run before the op. Link: http://lore.kernel.org/netdev/69b5ad67.a00a0220.3b25d1.001a.GAE@google.com Signed-off-by: Stanislav Fomichev --- net/wireless/nl80211.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 2225f5d0b124..ce5f25d4c87e 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -18192,7 +18192,7 @@ static int nl80211_pre_doit(const struct genl_split_ops *ops, __release(&rdev->wiphy.mtx); } if (!(internal_flags & NL80211_FLAG_NEED_RTNL)) - rtnl_unlock(); + __rtnl_unlock(); return 0; out_unlock: -- 2.53.0