[PATCH 4.9 63/76] ALSA: seq: Fix OOB-reads from strlcpy

From: Greg Kroah-Hartman
Date: Mon Apr 15 2019 - 14:48:45 EST


From: Zubin Mithra <zsm@xxxxxxxxxxxx>

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@xxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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;
@@ -1527,7 +1527,7 @@ 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));
snd_use_lock_free(&q->use_lock);

return 0;
@@ -1589,7 +1589,7 @@ 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;