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 7F1D347ECFB; Thu, 20 Aug 2026 17:57:28 +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=1787248649; cv=none; b=mB1RqseTDOOp7yV03TvvBGGc9dgA4zvyCR1yoHAS3WtE/9V7PQT0jCNnkwjqVBrGpX/QiZ9JZUk0V/2ZpAS6YDUr6SSMljhCEEZrerZALEf7xxvDIj5Kks76gHCLumRU4qUfh7w/FJv/Gsih769wU529SE8/lDVv3HzqZ88RVNc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787248649; c=relaxed/simple; bh=BA/ocHCa5uO9MdlsI95APa6vWoM34w7p/Ladu3yHf5o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tfpvGWZ2/8CtENz4BVMIBAlw1hfjeOPwKooBhpTFpn9MDZhQY8d3Ld5pEsLR86CgTgtVMOChDEEQlcUGdfiDk8MTXsaYMHbFilHoAJ2vbf6/MK7DgSEATEsUTE7VqqqtAVQQalBh18L4Lnc0Tz5gzPaI2nEb6EidWVXLGhhaRfk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FAmsm1ma; 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="FAmsm1ma" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA3861F000E9; Thu, 20 Aug 2026 17:57:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787248648; bh=BCKpje2eninCniNxCGRifqGewu1nphcjGadKqaUP9YI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FAmsm1maIp7/f9N5mPvYa66/dIFxN0eaz6JtkbyoDnGty3TrNEvS7h2ARy2Y/r/x8 0BMtJ2ong4K0BoiiwJSw1/tia5eNL/clQyriDvVcIBkG5oXCM9n9y3LgM+hXPFyuzH zcnoCojHTa3nD+JmDBiXxPiOVCD69d82rIFoaovQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com, Edward Adam Davis , Luiz Augusto von Dentz Subject: [PATCH 6.1 300/303] Bluetooth: hci_sock: Prevent race in socket write iter and sock bind Date: Thu, 20 Aug 2026 16:57:16 +0200 Message-ID: <20260820145302.485486297@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145253.200766705@linuxfoundation.org> References: <20260820145253.200766705@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Edward Adam Davis commit 89bb613511cc21ed5ba6bddc1c9b9ae9c0dad392 upstream. There is a potential race condition between sock bind and socket write iter. bind may free the same cmd via mgmt_pending before write iter sends the cmd, just as syzbot reported in UAF[1]. Here we use hci_dev_lock to synchronize the two, thereby avoiding the UAF mentioned in [1]. [1] syzbot reported: BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316 Read of size 8 at addr ffff888077164818 by task syz.0.17/5989 Call Trace: mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316 set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 Allocated by task 5989: mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296 set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 Freed by task 5991: mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline] mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257 mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314 Fixes: 6fe26f694c82 ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock") Reported-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80 Tested-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/hci_sock.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -1247,7 +1247,9 @@ static int hci_sock_bind(struct socket * goto done; } + hci_dev_lock(hdev); mgmt_index_removed(hdev); + hci_dev_unlock(hdev); err = hci_dev_open(hdev->id); if (err) {