From c709f14f0616482b67f9fbcb965e1493a03ff30b Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Wed, 20 Mar 2019 18:42:01 -0500 Subject: ALSA: seq: oss: Fix Spectre v1 vulnerability dev is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: sound/core/seq/oss/seq_oss_synth.c:626 snd_seq_oss_synth_make_info() warn: potential spectre issue 'dp->synths' [w] (local cap) Fix this by sanitizing dev before using it to index dp->synths. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/ Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva Signed-off-by: Takashi Iwai --- sound/core/seq/oss/seq_oss_synth.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'sound/core/seq') diff --git a/sound/core/seq/oss/seq_oss_synth.c b/sound/core/seq/oss/seq_oss_synth.c index 278ebb993122..c93945917235 100644 --- a/sound/core/seq/oss/seq_oss_synth.c +++ b/sound/core/seq/oss/seq_oss_synth.c @@ -617,13 +617,14 @@ int snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_info *inf) { struct seq_oss_synth *rec; + struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev); - if (dev < 0 || dev >= dp->max_synthdev) + if (!info) return -ENXIO; - if (dp->synths[dev].is_midi) { + if (info->is_midi) { struct midi_info minf; - snd_seq_oss_midi_make_info(dp, dp->synths[dev].midi_mapped, &minf); + snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf); inf->synth_type = SYNTH_TYPE_MIDI; inf->synth_subtype = 0; inf->nr_voices = 16; -- cgit v1.2.3 From 212ac181c158c09038c474ba68068be49caecebb Mon Sep 17 00:00:00 2001 From: Zubin Mithra Date: Thu, 4 Apr 2019 14:33:55 -0700 Subject: ALSA: seq: Fix OOB-reads from strlcpy 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 Reviewed-by: Guenter Roeck Cc: Signed-off-by: Takashi Iwai --- sound/core/seq/seq_clientmgr.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'sound/core/seq') diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c index 7d4640d1fe9f..38e7deab6384 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -1252,7 +1252,7 @@ static int snd_seq_ioctl_set_client_info(struct snd_seq_client *client, /* 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; @@ -1530,7 +1530,7 @@ static int snd_seq_ioctl_create_queue(struct snd_seq_client *client, void *arg) /* 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; @@ -1592,7 +1592,7 @@ static int snd_seq_ioctl_set_queue_info(struct snd_seq_client *client, queuefree(q); return -EPERM; } - strlcpy(q->name, info->name, sizeof(q->name)); + strscpy(q->name, info->name, sizeof(q->name)); queuefree(q); return 0; -- cgit v1.2.3