[PATCH 3.18 052/104] ALSA: seq: Fix OOB-reads from strlcpy

Greg Kroah-Hartman
2019-04-24T17:13:07Z

From: Zubin Mithra <zsm@chromium.org>

commit 212ac181c158c09038c474ba68068be49caecebb upstream.

When ioctl calls are made with non-null-terminated userspace strings,
strlcpy causes an OOB-read from within strlen. Fix by changing to use
strscpy instead.

Signed-off-by: Zubin Mithra <zsm@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/core/seq/seq_clientmgr.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -1249,7 +1249,7 @@ static int snd_seq_ioctl_set_client_info

/* fill the info fields */
if (client_info.name[0])
- strlcpy(client->name, client_info.name, sizeof(client->name));
+ strscpy(client->name, client_info.name, sizeof(client->name));

client->filter = client_info.filter;
client->event_lost = client_info.event_lost;
@@ -1564,7 +1564,7 @@ static int snd_seq_ioctl_create_queue(st
/* set queue name */
if (! info.name[0])
snprintf(info.name, sizeof(info.name), "Queue-%d", q->queue);
- strlcpy(q->name, info.name, sizeof(q->name));
+ strscpy(q->name, info.name, sizeof(q->name));
queuefree(q);

if (copy_to_user(arg, &info, sizeof(info)))
@@ -1642,7 +1642,7 @@ static int snd_seq_ioctl_set_queue_info(
queuefree(q);
return -EPERM;
}
- strlcpy(q->name, info.name, sizeof(q->name));
+ strscpy(q->name, info.name, sizeof(q->name));
queuefree(q);

return 0;