From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37035) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gSica-0000eK-Rc for qemu-devel@nongnu.org; Fri, 30 Nov 2018 08:14:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gSicP-0003dk-EG for qemu-devel@nongnu.org; Fri, 30 Nov 2018 08:14:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53040) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gSicN-0003Qh-6q for qemu-devel@nongnu.org; Fri, 30 Nov 2018 08:14:03 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 18C593001FF7 for ; Fri, 30 Nov 2018 13:14:01 +0000 (UTC) From: Markus Armbruster References: <20181130111222.25386-1-kraxel@redhat.com> <20181130111222.25386-2-kraxel@redhat.com> Date: Fri, 30 Nov 2018 14:13:56 +0100 In-Reply-To: <20181130111222.25386-2-kraxel@redhat.com> (Gerd Hoffmann's message of "Fri, 30 Nov 2018 12:12:21 +0100") Message-ID: <87woouk8rv.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH for-3.1 1/2] usb-mtp: fix utf16_to_str List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: qemu-devel@nongnu.org Gerd Hoffmann writes: > Make utf16_to_str return an allocated string. Remove the assumtion that > the number of string bytes equals the number of utf16 chars (which is > only true for ascii chars). Instead call wcstombs twice, once to figure > the storage size and once for the actual conversion (as suggested by the > wcstombs manpage). > > Reported-by: Michael Hanselmann (hansmi.ch) > Signed-off-by: Gerd Hoffmann > --- > hw/usb/dev-mtp.c | 17 +++++++++++------ > 1 file changed, 11 insertions(+), 6 deletions(-) > > diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c > index 00a3691bae..fbe1ace035 100644 > --- a/hw/usb/dev-mtp.c > +++ b/hw/usb/dev-mtp.c > @@ -1593,17 +1593,22 @@ static void usb_mtp_cancel_packet(USBDevice *dev, USBPacket *p) > fprintf(stderr, "%s\n", __func__); > } > > -static void utf16_to_str(uint8_t len, uint16_t *arr, char *name) > +static char *utf16_to_str(uint8_t len, uint16_t *arr) > { > - int count; > - wchar_t *wstr = g_new0(wchar_t, len); > + wchar_t *wstr = g_new0(wchar_t, len + 1); > + int count, dlen; > + char *dest; > > for (count = 0; count < len; count++) { > wstr[count] = (wchar_t)arr[count]; > } > + wstr[count] = 0; > > - wcstombs(name, wstr, len); > + dlen = wcstombs(NULL, wstr, 0) + 1; > + dest = g_malloc(dlen); > + wcstombs(dest, wstr, dlen); > g_free(wstr); > + return dest; > } Preexisting: casting uint16_t to wchar_t is iffy for at least two reasons: * When wchar_t is UCS-4, things fall apart for surrogate pairs. For instance, the surrogate pair uint16_t arr = { 0xD834, 0xDD1E }; should map to the single wchar_t 0x1D11E. * wchar_t needn't even be Unicode. It might well be on any host we care for, but are you *sure*? I guess g_utf16_to_utf8() would be differently wrong: it converts to UTF-8, but we need to convert to the current locale's multibyte string. > > /* Wrapper around write, returns 0 on failure */ > @@ -1703,7 +1708,7 @@ static void usb_mtp_write_metadata(MTPState *s) > { > MTPData *d = s->data_out; > ObjectInfo *dataset = (ObjectInfo *)d->data; > - char *filename = g_new0(char, dataset->length); > + char *filename; > MTPObject *o; > MTPObject *p = usb_mtp_object_lookup(s, s->dataset.parent_handle); > uint32_t next_handle = s->next_handle; > @@ -1711,7 +1716,7 @@ static void usb_mtp_write_metadata(MTPState *s) > assert(!s->write_pending); > assert(p != NULL); > > - utf16_to_str(dataset->length, dataset->filename, filename); > + filename = utf16_to_str(dataset->length, dataset->filename); > > o = usb_mtp_object_lookup_name(p, filename, dataset->length); > if (o != NULL) {