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 5D4E911CA6; Mon, 23 Oct 2023 11:51:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hfAvDVnQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 981E7C433C8; Mon, 23 Oct 2023 11:51:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698061897; bh=xM52sSkaFA0z/TYUcVV4TvzfMFXhRnUHTMwW0mCBX7U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hfAvDVnQ2DlA40O+IGjAvY5tAX1yl8qMfdnbbl8R8S3TrPVb3Lna/GX4LX3eiIQn/ hJ5LT41YAQ4dD636spIafwUqJxqbnlJS2zPU6vBLC/bh0ooPcco0dWtgL0FSlLv2yO VLgh0rf7BRl5+tzqKz1CzT/fSe92S6XtJ+GGpAk8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luiz Augusto von Dentz , Edward AD , Marcel Holtmann , Johan Hedberg , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, Kees Cook Subject: [PATCH 5.10 201/202] Bluetooth: hci_sock: Correctly bounds check and pad HCI_MON_NEW_INDEX name Date: Mon, 23 Oct 2023 12:58:28 +0200 Message-ID: <20231023104832.286999580@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104826.569169691@linuxfoundation.org> References: <20231023104826.569169691@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook commit cb3871b1cd135a6662b732fbc6b3db4afcdb4a64 upstream. The code pattern of memcpy(dst, src, strlen(src)) is almost always wrong. In this case it is wrong because it leaves memory uninitialized if it is less than sizeof(ni->name), and overflows ni->name when longer. Normally strtomem_pad() could be used here, but since ni->name is a trailing array in struct hci_mon_new_index, compilers that don't support -fstrict-flex-arrays=3 can't tell how large this array is via __builtin_object_size(). Instead, open-code the helper and use sizeof() since it will work correctly. Additionally mark ni->name as __nonstring since it appears to not be a %NUL terminated C string. Cc: Luiz Augusto von Dentz Cc: Edward AD Cc: Marcel Holtmann Cc: Johan Hedberg Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: linux-bluetooth@vger.kernel.org Cc: netdev@vger.kernel.org Fixes: 18f547f3fc07 ("Bluetooth: hci_sock: fix slab oob read in create_monitor_event") Link: https://lore.kernel.org/lkml/202310110908.F2639D3276@keescook/ Signed-off-by: Kees Cook Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- include/net/bluetooth/hci_mon.h | 2 +- net/bluetooth/hci_sock.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) --- a/include/net/bluetooth/hci_mon.h +++ b/include/net/bluetooth/hci_mon.h @@ -56,7 +56,7 @@ struct hci_mon_new_index { __u8 type; __u8 bus; bdaddr_t bdaddr; - char name[8]; + char name[8] __nonstring; } __packed; #define HCI_MON_NEW_INDEX_SIZE 16 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -438,7 +438,8 @@ static struct sk_buff *create_monitor_ev ni->type = hdev->dev_type; ni->bus = hdev->bus; bacpy(&ni->bdaddr, &hdev->bdaddr); - memcpy(ni->name, hdev->name, strlen(hdev->name)); + memcpy_and_pad(ni->name, sizeof(ni->name), hdev->name, + strnlen(hdev->name, sizeof(ni->name)), '\0'); opcode = cpu_to_le16(HCI_MON_NEW_INDEX); break;