From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 BF8EA3A63F1; Tue, 20 Jan 2026 08:12:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768896757; cv=none; b=CpoYWnrYMtTYFemWgFAfUm8Hsu/stNrOzxpcxFEXtMQsoK7RGN7nA3GNcoIj7nlbqAgAfGUlIi6cFdWjkj9N6i5lzBchg065teBTrgCWT4G8tUk2VfTUjKttbcDWx7beEv2PMOs4dQPB67Wh4ll+tKU0peeG+NBCNzM3vBAO3io= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768896757; c=relaxed/simple; bh=PT6mZhuCrSYblI3h5qXU55P6G9Ktq/aLX/t/ucL6RPU=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=QnlqZPPZ4b1sN2SuPskoJ++fZH6ckbj217xd45XpLGQiEMufomxUJN83A1wHZvsbc4/7FV5mNSd+43Lt9jXc0GvTqvSO/n60e+3g39IiwsGB8ptAZrwt+4p0FMglTLN958fUyxbki4wgBPJUvwGNpFypj9+In6ENc9iHUQI/6UY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=ZD7WRlCk; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="ZD7WRlCk" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=PT6mZhuCrSYblI3h5qXU55P6G9Ktq/aLX/t/ucL6RPU=; t=1768896755; x=1770106355; b=ZD7WRlCk196HlnQo75/aomHiQC5Qi5ulGLIHR1oOcB2UEs5 CegOixUeXChb2A3tbnRfO3hyGDlxrUTkRiIOVZEcJDT1At+8S9gCmHVXW+1qQAPtjV4HpwKSSSAjG 6sqM+lzWUhFKIc7+atOsLhwzmpqOkpyO9+JmwSVmkpSAirSW/ihbEdZKlvDV5cU1AXuU7DxOxLtYb AWEu6Fsg2UVAvSMj07IeMbzl0i3oX4OF84lHDA6n1WVCV0H3Dp6tGew4YUZH1yChscfaYqJwZlCVf M3qu+GDWLDRH4vpO5JAX1w0D0PQBADPgcyeKuHBooNNHmtXZzoH89cFCsN169RZQ==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1vi6qm-0000000Ghct-26ZE; Tue, 20 Jan 2026 09:12:32 +0100 Message-ID: <35581fc687d151b2b4fabccb6952d567cac65240.camel@sipsolutions.net> Subject: Re: [PATCH] wifi: mac80211: fix NULL pointer dereference in ieee80211_mesh_build_beacon() From: Johannes Berg To: Jeongjun Park Cc: linux-wireless@vger.kernel.org, syzbot+81cd9dc1596563141d19@syzkaller.appspotmail.com, linux-kernel@vger.kernel.org Date: Tue, 20 Jan 2026 09:12:31 +0100 In-Reply-To: <20260119150031.201832-1-aha310510@gmail.com> (sfid-20260119_160223_485174_E37F681D) References: <20260119150031.201832-1-aha310510@gmail.com> (sfid-20260119_160223_485174_E37F681D) Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-2.fc42) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned On Tue, 2026-01-20 at 00:00 +0900, Jeongjun Park wrote: > NULL pointer dereference bug occurs because ieee80211_mesh_build_beacon() > does not check the return value of ieee80211_get_sband(). >=20 > Therefore, we need to add a return value check to prevent this. No we don't, please try to understand the code, and why it can even get here when the mesh interface isn't operating. johannes