ALSA: rme9652: fix format overflow warnings

gcc-7 warns about a possible sprintf format string overflow with a
temporary buffer that is used to print from another buffer of the same
size:

sound/pci/rme9652/hdspm.c: In function 'snd_hdspm_create_alsa_devices':
sound/pci/rme9652/hdspm.c:2123:17: error: ' MIDIoverMADI' directive writing 13 bytes into a region of size between 1 and 32 [-Werror=format-overflow=]

This extends the temporary buffer to twice the size, and changes
the code to use the safer snprintf() across the entire file.
The longer buffer is still necessary to avoid a format-truncation
warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/rme9652/hdspm.c b/sound/pci/rme9652/hdspm.c
index 254c3d0..2a3a916 100644 (file)
--- a/sound/pci/rme9652/hdspm.c
+++ b/sound/pci/rme9652/hdspm.c
@@ -2061,7 +2061,7 @@ static int snd_hdspm_create_midi(struct snd_card *card,
                                 struct hdspm *hdspm, int id)
 {
        int err;
-       char buf[32];
+       char buf[64];
 
        hdspm->midi[id].id = id;
        hdspm->midi[id].hdspm = hdspm;
@@ -2120,19 +2120,23 @@ static int snd_hdspm_create_midi(struct snd_card *card,
        if ((id < 2) || ((2 == id) && ((MADI == hdspm->io_type) ||
                                        (MADIface == hdspm->io_type)))) {
                if ((id == 0) && (MADIface == hdspm->io_type)) {
-                       sprintf(buf, "%s MIDIoverMADI", card->shortname);
+                       snprintf(buf, sizeof(buf), "%s MIDIoverMADI",
+                                card->shortname);
                } else if ((id == 2) && (MADI == hdspm->io_type)) {
-                       sprintf(buf, "%s MIDIoverMADI", card->shortname);
+                       snprintf(buf, sizeof(buf), "%s MIDIoverMADI",
+                                card->shortname);
                } else {
-                       sprintf(buf, "%s MIDI %d", card->shortname, id+1);
+                       snprintf(buf, sizeof(buf), "%s MIDI %d",
+                                card->shortname, id+1);
                }
                err = snd_rawmidi_new(card, buf, id, 1, 1,
                                &hdspm->midi[id].rmidi);
                if (err < 0)
                        return err;
 
-               sprintf(hdspm->midi[id].rmidi->name, "%s MIDI %d",
-                               card->id, id+1);
+               snprintf(hdspm->midi[id].rmidi->name,
+                        sizeof(hdspm->midi[id].rmidi->name),
+                        "%s MIDI %d", card->id, id+1);
                hdspm->midi[id].rmidi->private_data = &hdspm->midi[id];
 
                snd_rawmidi_set_ops(hdspm->midi[id].rmidi,
@@ -2148,14 +2152,16 @@ static int snd_hdspm_create_midi(struct snd_card *card,
                        SNDRV_RAWMIDI_INFO_DUPLEX;
        } else {
                /* TCO MTC, read only */
-               sprintf(buf, "%s MTC %d", card->shortname, id+1);
+               snprintf(buf, sizeof(buf), "%s MTC %d",
+                        card->shortname, id+1);
                err = snd_rawmidi_new(card, buf, id, 1, 1,
                                &hdspm->midi[id].rmidi);
                if (err < 0)
                        return err;
 
-               sprintf(hdspm->midi[id].rmidi->name,
-                               "%s MTC %d", card->id, id+1);
+               snprintf(hdspm->midi[id].rmidi->name,
+                        sizeof(hdspm->midi[id].rmidi->name),
+                        "%s MTC %d", card->id, id+1);
                hdspm->midi[id].rmidi->private_data = &hdspm->midi[id];
 
                snd_rawmidi_set_ops(hdspm->midi[id].rmidi,
@@ -6869,7 +6875,8 @@ static int snd_hdspm_create(struct snd_card *card,
                 * when running with multiple cards.
                 */
                if (NULL == id[hdspm->dev] && hdspm->serial != 0xFFFFFF) {
-                       sprintf(card->id, "HDSPMx%06x", hdspm->serial);
+                       snprintf(card->id, sizeof(card->id),
+                                "HDSPMx%06x", hdspm->serial);
                        snd_card_set_id(card, card->id);
                }
        }
@@ -6954,17 +6961,18 @@ static int snd_hdspm_probe(struct pci_dev *pci,
        }
 
        if (hdspm->io_type != MADIface) {
-               sprintf(card->shortname, "%s_%x",
-                       hdspm->card_name,
-                       hdspm->serial);
-               sprintf(card->longname, "%s S/N 0x%x at 0x%lx, irq %d",
-                       hdspm->card_name,
-                       hdspm->serial,
-                       hdspm->port, hdspm->irq);
+               snprintf(card->shortname, sizeof(card->shortname), "%s_%x",
+                       hdspm->card_name, hdspm->serial);
+               snprintf(card->longname, sizeof(card->longname),
+                        "%s S/N 0x%x at 0x%lx, irq %d",
+                        hdspm->card_name, hdspm->serial,
+                        hdspm->port, hdspm->irq);
        } else {
-               sprintf(card->shortname, "%s", hdspm->card_name);
-               sprintf(card->longname, "%s at 0x%lx, irq %d",
-                               hdspm->card_name, hdspm->port, hdspm->irq);
+               snprintf(card->shortname, sizeof(card->shortname), "%s",
+                        hdspm->card_name);
+               snprintf(card->longname, sizeof(card->longname),
+                        "%s at 0x%lx, irq %d",
+                        hdspm->card_name, hdspm->port, hdspm->irq);
        }
 
        err = snd_card_register(card);