From nobody Sat Feb 7 17:04:30 2026 Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) (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 0879513B293 for ; Thu, 5 Feb 2026 03:52:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770263563; cv=none; b=ng71FuIfwKz+3sd7GEcsRGtIkvw4GmmST5B8TKL8wniYhdFZHGwgl/NGbEkEtnt/mcLghOmKPnlHkvX36Ytq9hTIihNXV3ve9D9NnjX4BbeB15pWDwO31hECHPBat1COmV6OOZGJEMccpi2U/Y1CCNFN5jVQN2G22xVmOy8WBoc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770263563; c=relaxed/simple; bh=he/euZIb+7nGDowd6ofIEKauu0OYEXlKSqHjuCdgq2I=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=SmSi4o7F5NW8oN3dBx5QCgJ/ULy2dSIWspP6TuWX3hzBWjM+MCYjWCSfQzKz7n8Sb8rEJezGR0T8g9m9d6kdB/pfXlRVCDtv23IxI+O3IeK1hqahUUgzAtJw2tWBfPWlM04JzkZ0FgcUYpokBT2K7E5Xb3EWbknjEWA4qPtDAJo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Qu26q0Go; arc=none smtp.client-ip=209.85.210.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Qu26q0Go" Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-823081bb15fso296821b3a.3 for ; Wed, 04 Feb 2026 19:52:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1770263562; x=1770868362; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=v+kdKXzJ6z8gg3py8m3rnJr90/PdPYODZxYKzc7gJDw=; b=Qu26q0Gov3tSLkc41cxFkh2rskN0jjXMWgoOAtc2cVnH2Slx9eL5yrOU7ZQyIWyyYw /CPtk0zVd/rNePQ5JVsafFJiDbllWqXvpgJA8hA0oZqW2Yz4Dak1PyArzcWappQZ+CkG fqXKuNQ8+zbSFbpasIJ5EGXa9sNOhR2Cc6LJGYxrmKXQ0YuAqToTn2xoxUVnJbSHYl7d +LZagpdCmfjOZBXihnwWy8P+oJ4anhPT+yG6T5wm7II0Je5vP9/PAag8qWoVJaTOMJKP KWGt9wK0rk28rMjf10+Ga+cJWlC2cpJCJr7okrS29u6PFewdEaC7r4c71rxbFXHLtkGJ zUVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770263562; x=1770868362; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=v+kdKXzJ6z8gg3py8m3rnJr90/PdPYODZxYKzc7gJDw=; b=le6YEe4KuRDkxA5KySwWXeoXEGxo9+u497RS31eT6j/Ca7A7nnxG5Djf33JkMCi9NM CFsXdwwOOfd3RqJpe3kvigW+Af2MJ4i09rCUHZ9pAJGIN96Zoe1N3WuVvy3pqgJEWJRb cHn5+4xlY37EAzoTPv2C7bqkhV1qOzIyzobtun0bGDtS/GdNy3SJLRaFusMMF2hMTx76 pSNc2EIgy9bJRn/wDgZPWs2rFPHx9Q2mYKCvFM8G3E1cc4W7pC3DJ31j1+DGn+ZK1Hrq o6QEFcBXmftbEI52KjKK/vKIuO4CliTATNbC/ITm8NHBWXUT4aSWtb++utZD1vJbJaUy 2FtQ== X-Forwarded-Encrypted: i=1; AJvYcCVC24i3lpaYwAP3X0+2KHMC3ucKi8cNpTig0HcgF49xPAFmcRjHhhflH9qHi9z+sIhYSjMgmL3WDN5k3ZM=@vger.kernel.org X-Gm-Message-State: AOJu0YxfbC9geG35OESvalkz5k+CVB9LIc/SU0xfrLET7R8L7ycGcBxh KAbgn5Gwr4/oaY+j3CNXaV2nmnVOAdb55ZyC+/v0sUPXPpezKzlKt9hz X-Gm-Gg: AZuq6aIKEm7MX+UNQikVqPyuTu2Nj2K2kIHrtrrp89WO3fNsT7/SWTn2+4TAP0IAHLI 58CbPeLRpW7VzZezDSAYBq9r36pyBGCSuk+J/MuPNNPAAj6dVZj3P2qeOFIEj8NzHfZXUYdsFFM hS75mOAkYupT9xg6gr2fqI7n+NZy1x5qhwNvRzFIq7p8U1R9SXr0zKa8tkVjFSr2mangsCRTKHO KKB/9Sqf70War/Yyr0XePu3Y2naJZ7noudHsVLFVHvSXuL2b3fZ6M/R0CRvUvy4A9EczavDjlBb KIUfoavcBveICVEXfqZvdb93IG0PCTCsMUylqb6vgTS7YOSHLUjFeFPnRfRaURW0yWOGRIwt/dd w+TQ8HkE5sBZ1wymRki6+pVlQM8k3iRVMxMA0rp33D5LdQr50K5k+gufjS7NIQgO5RNV7mYUVWL xcZsGw7Pn0vLg= X-Received: by 2002:a05:6a00:3d54:b0:81f:44f9:7c1a with SMTP id d2e1a72fcca58-8241c188060mr5723484b3a.3.1770263562235; Wed, 04 Feb 2026 19:52:42 -0800 (PST) Received: from mint.. ([2401:4900:7925:4bf8:455e:d5c9:a17:3da7]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-8241d435319sm4018523b3a.33.2026.02.04.19.52.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Feb 2026 19:52:41 -0800 (PST) From: Dhyan K Prajapati To: johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Dhyan K Prajapati Subject: [PATCH] mac80211: fix NULL pointer dereference when switching to monitor mode Date: Thu, 5 Feb 2026 09:22:23 +0530 Message-ID: <20260205035223.20411-1-dhyan19022009@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When switching an interface to monitor mode, ieee80211_link_info_change_not= ify() incorrectly sends BSS change notifications to drivers, even though monitor interfaces have no associated BSS context. This causes NULL pointer derefer= ences in drivers like iwldvm. The bug occurs because the current code only returns early for monitor inte= rfaces when WANT_MONITOR_VIF is NOT set. When WANT_MONITOR_VIF IS set, execution b= reaks from the switch statement and falls through to drv_link_info_changed(), whi= ch triggers the crash when the driver attempts to dereference link->conf->bss. Crash trace: RIP: iwlagn_bss_info_changed+0x19d/0x640 [iwldvm] Code: 49 8b 46 10 <8b> 10 RAX: 0000000000000000 (NULL link->conf->bss) Fix by unconditionally returning early for IFTYPE_MONITOR, consistent with IFTYPE_AP_VLAN handling. Also simplify by merging both cases. Device: Intel Centrino Advanced-N 6205 Signed-off-by: Dhyan K Prajapati --- net/mac80211/main.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/net/mac80211/main.c b/net/mac80211/main.c index b05e313c7..bc93df21e 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -412,11 +412,8 @@ void ieee80211_link_info_change_notify(struct ieee8021= 1_sub_if_data *sdata, =20 switch (sdata->vif.type) { case NL80211_IFTYPE_AP_VLAN: - return; case NL80211_IFTYPE_MONITOR: - if (!ieee80211_hw_check(&local->hw, WANT_MONITOR_VIF)) - return; - break; + return; default: break; } --=20 2.43.0