From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 F30E7519E13; Wed, 30 Sep 2026 17:46:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790365; cv=none; b=SgCkDKN/eg6CG+ztFwH87jCLMExlAzYkN5QA0onNkHYiD0tTF3ZCldkLjM15RaCV/0UOH0SsZVmU3bfqZXP9B5zN6Z9v73q0jlJun3GiLznO2A83OrTeh9vhCGqAAVQp7WUK5wvhTj5UsaHds5Bkk51mxNmwTX75ImALtNVvwCU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790365; c=relaxed/simple; bh=cI6aXbWo5VUXxjX1oDKumRadhgmLeq8A6Gt4Z3Sqyy4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h8ylIN1XcM8NLTkTkWaSeHJ+4PT2cm/RttGBAG0TL+YljkYYEWlRsJc7m4Y71xeYBvL3gu2txMJXTHJlMRikcY6QThIXMGIDfAJHSlhKTHz3Nk54cpswjtSh6gCTNw/S1WCunsvwbPmeJ94XjBkvvu8GDFAMnkqT38KTF/rS8uI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=g3O0kMme; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="g3O0kMme" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5AC8D1F000FF; Wed, 30 Sep 2026 17:46:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790790363; bh=nfOy3gsBXnx+awSmXTm/iFXi14waVjmewcv+qBd4Pos=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=g3O0kMme20sSOglgqfldzsPbtxKa9+ifP4Nakh2kCoB9siAkSYSCXYTDpREB1fsie 7jvpbY0ELJ/s1BZSRHROYArOVXbU4TQj3q13ePDoWDaGKyZvg7NyZzxmFIjStLuMxM RBG2t6xrN34qVB3AsHDRm4GhAy92+B3xoERL9xSk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Devin Wittmayer , Johannes Berg , Sasha Levin Subject: [PATCH 6.12 803/877] wifi: mac80211: refuse to make a monitor active when it has no queue Date: Wed, 30 Sep 2026 17:28:34 +0200 Message-ID: <20260930152432.044777139@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152414.738996857@linuxfoundation.org> References: <20260930152414.738996857@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Devin Wittmayer [ Upstream commit 2b04d6556964ae9f89819b86a0a7801e39c3aae5 ] A monitor interface only gets a TXQ if it's created active, and one can't be added later. Setting the flag on a down interface is still allowed, so the driver is handed a monitor with no queue. ath9k dereferences it: BUG: kernel NULL pointer dereference, address: 0000000000000066 RIP: 0010:ath_tx_node_init+0x49/0x170 [ath9k] ath9k_add_interface+0x10c/0x140 [ath9k] drv_add_interface+0x54/0x250 [mac80211] ieee80211_do_open+0x32f/0x800 [mac80211] Reached with CAP_NET_ADMIN by "iw dev X set monitor active" followed by "ip link set X up". RTNL is held, so netlink operations block behind it. Refuse the flag when there is no queue to give. Fixes: 79af1f866193 ("mac80211: avoid allocating TXQs that won't be used") Cc: stable@vger.kernel.org Signed-off-by: Devin Wittmayer Link: https://patch.msgid.link/20260904200338.10829-1-lucid_duck@justthetip.ca Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/mac80211/cfg.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -116,6 +116,10 @@ static int ieee80211_set_mon_options(str return -EBUSY; } + /* TXQs are reserved in ieee80211_if_add() and cannot be added later */ + if ((params->flags & MONITOR_FLAG_ACTIVE) && !sdata->vif.txq) + return -EOPNOTSUPP; + /* validate whether MU-MIMO can be configured */ if (!ieee80211_hw_check(&local->hw, WANT_MONITOR_VIF) && (params->vht_mumimo_groups || params->vht_mumimo_follow_addr))