From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0B4E53570A7; Wed, 3 Dec 2025 16:56:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764781002; cv=none; b=uYwtzOva9AJhVppOBsqymvLKwjNUi5fYAfo9upwmngJBBuT+SouQHMKhe8cW9ImPMTBFYahX+OrljSWSYbosKj489lsg2+DZYxecVounNIum24gBwDPaR0A3XxHK2vzFzQ5Z8wpn6VRTVJTJ+dy868i9DKrcmLKxJl7on8qVwmQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764781002; c=relaxed/simple; bh=2vHUP3/wegvbWGJQCrnj9qho8F+/mTtFa4bYsqRoi7Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Yn6TIGgxFVVRqQG7lLW6OFuiD6dskLbvgbTcD1GvykLXflBKDx3E4DpGjb+YTcFfT/qJI1wt3mGQOtGAoKHLGfTZ8mZ+qI4fQty2vq3JgRzLK3dDj+F3ALnU5ADWEIX0hlJ4LsKH+Rix1srvx6Qv/YR8iML0WeGO8wMURPv4/0I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EZqnQAL7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="EZqnQAL7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BA23C4CEF5; Wed, 3 Dec 2025 16:56:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764781001; bh=2vHUP3/wegvbWGJQCrnj9qho8F+/mTtFa4bYsqRoi7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EZqnQAL77C9/7D56DmiRz48H8HVP2MmnZFhLP0lHbujTbz4N/pYfiB64BY/8uSrYi XvX8TjhAtrvr7WldKUT0eSk6Zd8GOZRTE34DPrlpiLQLNHw0lfu6PPpz1Dtl2EHkXg fxZBVbYGj19aAHRZv2r0SIXmt5XHBh6c4rn8NXYQ= 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 , Sasha Levin Subject: [PATCH 6.6 05/93] Bluetooth: hci_sock: Prevent race in socket write iter and sock bind Date: Wed, 3 Dec 2025 16:28:58 +0100 Message-ID: <20251203152336.701516958@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152336.494201426@linuxfoundation.org> References: <20251203152336.494201426@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Edward Adam Davis [ Upstream commit 89bb613511cc21ed5ba6bddc1c9b9ae9c0dad392 ] 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: Sasha Levin --- net/bluetooth/hci_sock.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index d2613bd3e6db0..8b3ef088ed14e 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -1304,7 +1304,9 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr, goto done; } + hci_dev_lock(hdev); mgmt_index_removed(hdev); + hci_dev_unlock(hdev); err = hci_dev_open(hdev->id); if (err) { -- 2.51.0