* Patch "ALSA: seq: More protection for concurrent write and ioctl races" has been added to the 4.14-stable tree
@ 2018-03-12 15:40 gregkh
0 siblings, 0 replies; only message in thread
From: gregkh @ 2018-03-12 15:40 UTC (permalink / raw
To: tiwai, gregkh, long7573, nstange, stable; +Cc: stable, stable-commits
This is a note to let you know that I've just added the patch titled
ALSA: seq: More protection for concurrent write and ioctl races
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-seq-more-protection-for-concurrent-write-and-ioctl-races.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From 7bd80091567789f1c0cb70eb4737aac8bcd2b6b9 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Mon, 5 Mar 2018 22:06:09 +0100
Subject: ALSA: seq: More protection for concurrent write and ioctl races
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From: Takashi Iwai <tiwai@suse.de>
commit 7bd80091567789f1c0cb70eb4737aac8bcd2b6b9 upstream.
This patch is an attempt for further hardening against races between
the concurrent write and ioctls. The previous fix d15d662e89fc
("ALSA: seq: Fix racy pool initializations") covered the race of the
pool initialization at writer and the pool resize ioctl by the
client->ioctl_mutex (CVE-2018-1000004). However, basically this mutex
should be applied more widely to the whole write operation for
avoiding the unexpected pool operations by another thread.
The only change outside snd_seq_write() is the additional mutex
argument to helper functions, so that we can unlock / relock the given
mutex temporarily during schedule() call for blocking write.
Fixes: d15d662e89fc ("ALSA: seq: Fix racy pool initializations")
Reported-by: 范龙飞 <long7573@126.com>
Reported-by: Nicolai Stange <nstange@suse.de>
Reviewed-and-tested-by: Nicolai Stange <nstange@suse.de>
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 | 18 +++++++++++-------
sound/core/seq/seq_fifo.c | 2 +-
sound/core/seq/seq_memory.c | 14 ++++++++++----
sound/core/seq/seq_memory.h | 3 ++-
4 files changed, 24 insertions(+), 13 deletions(-)
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -906,7 +906,8 @@ int snd_seq_dispatch_event(struct snd_se
static int snd_seq_client_enqueue_event(struct snd_seq_client *client,
struct snd_seq_event *event,
struct file *file, int blocking,
- int atomic, int hop)
+ int atomic, int hop,
+ struct mutex *mutexp)
{
struct snd_seq_event_cell *cell;
int err;
@@ -944,7 +945,8 @@ static int snd_seq_client_enqueue_event(
return -ENXIO; /* queue is not allocated */
/* allocate an event cell */
- err = snd_seq_event_dup(client->pool, event, &cell, !blocking || atomic, file);
+ err = snd_seq_event_dup(client->pool, event, &cell, !blocking || atomic,
+ file, mutexp);
if (err < 0)
return err;
@@ -1013,12 +1015,11 @@ static ssize_t snd_seq_write(struct file
return -ENXIO;
/* allocate the pool now if the pool is not allocated yet */
+ mutex_lock(&client->ioctl_mutex);
if (client->pool->size > 0 && !snd_seq_write_pool_allocated(client)) {
- mutex_lock(&client->ioctl_mutex);
err = snd_seq_pool_init(client->pool);
- mutex_unlock(&client->ioctl_mutex);
if (err < 0)
- return -ENOMEM;
+ goto out;
}
/* only process whole events */
@@ -1069,7 +1070,7 @@ static ssize_t snd_seq_write(struct file
/* ok, enqueue it */
err = snd_seq_client_enqueue_event(client, &event, file,
!(file->f_flags & O_NONBLOCK),
- 0, 0);
+ 0, 0, &client->ioctl_mutex);
if (err < 0)
break;
@@ -1080,6 +1081,8 @@ static ssize_t snd_seq_write(struct file
written += len;
}
+ out:
+ mutex_unlock(&client->ioctl_mutex);
return written ? written : err;
}
@@ -2259,7 +2262,8 @@ static int kernel_client_enqueue(int cli
if (! cptr->accept_output)
result = -EPERM;
else /* send it */
- result = snd_seq_client_enqueue_event(cptr, ev, file, blocking, atomic, hop);
+ result = snd_seq_client_enqueue_event(cptr, ev, file, blocking,
+ atomic, hop, NULL);
snd_seq_client_unlock(cptr);
return result;
--- a/sound/core/seq/seq_fifo.c
+++ b/sound/core/seq/seq_fifo.c
@@ -125,7 +125,7 @@ int snd_seq_fifo_event_in(struct snd_seq
return -EINVAL;
snd_use_lock_use(&f->use_lock);
- err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
+ err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL, NULL); /* always non-blocking */
if (err < 0) {
if ((err == -ENOMEM) || (err == -EAGAIN))
atomic_inc(&f->overflow);
--- a/sound/core/seq/seq_memory.c
+++ b/sound/core/seq/seq_memory.c
@@ -220,7 +220,8 @@ void snd_seq_cell_free(struct snd_seq_ev
*/
static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
struct snd_seq_event_cell **cellp,
- int nonblock, struct file *file)
+ int nonblock, struct file *file,
+ struct mutex *mutexp)
{
struct snd_seq_event_cell *cell;
unsigned long flags;
@@ -244,7 +245,11 @@ static int snd_seq_cell_alloc(struct snd
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&pool->output_sleep, &wait);
spin_unlock_irq(&pool->lock);
+ if (mutexp)
+ mutex_unlock(mutexp);
schedule();
+ if (mutexp)
+ mutex_lock(mutexp);
spin_lock_irq(&pool->lock);
remove_wait_queue(&pool->output_sleep, &wait);
/* interrupted? */
@@ -287,7 +292,7 @@ __error:
*/
int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
struct snd_seq_event_cell **cellp, int nonblock,
- struct file *file)
+ struct file *file, struct mutex *mutexp)
{
int ncells, err;
unsigned int extlen;
@@ -304,7 +309,7 @@ int snd_seq_event_dup(struct snd_seq_poo
if (ncells >= pool->total_elements)
return -ENOMEM;
- err = snd_seq_cell_alloc(pool, &cell, nonblock, file);
+ err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
if (err < 0)
return err;
@@ -330,7 +335,8 @@ int snd_seq_event_dup(struct snd_seq_poo
int size = sizeof(struct snd_seq_event);
if (len < size)
size = len;
- err = snd_seq_cell_alloc(pool, &tmp, nonblock, file);
+ err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
+ mutexp);
if (err < 0)
goto __error;
if (cell->event.data.ext.ptr == NULL)
--- a/sound/core/seq/seq_memory.h
+++ b/sound/core/seq/seq_memory.h
@@ -66,7 +66,8 @@ struct snd_seq_pool {
void snd_seq_cell_free(struct snd_seq_event_cell *cell);
int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
- struct snd_seq_event_cell **cellp, int nonblock, struct file *file);
+ struct snd_seq_event_cell **cellp, int nonblock,
+ struct file *file, struct mutex *mutexp);
/* return number of unused (free) cells */
static inline int snd_seq_unused_cells(struct snd_seq_pool *pool)
Patches currently in stable-queue which might be from tiwai@suse.de are
queue-4.14/alsa-seq-don-t-allow-resizing-pool-in-use.patch
queue-4.14/documentation-sphinx-fix-directive-import-error.patch
queue-4.14/alsa-hda-add-dock-and-led-support-for-hp-probook-640-g2.patch
queue-4.14/alsa-hda-realtek-make-dock-sound-work-on-thinkpad-l570.patch
queue-4.14/alsa-hda-realtek-limit-mic-boost-on-t480.patch
queue-4.14/alsa-hda-add-dock-and-led-support-for-hp-elitebook-820-g3.patch
queue-4.14/alsa-seq-more-protection-for-concurrent-write-and-ioctl-races.patch
queue-4.14/alsa-hda-realtek-add-support-headset-mode-for-dell-wyse.patch
queue-4.14/alsa-hda-realtek-add-headset-mode-support-for-dell-laptop.patch
queue-4.14/alsa-hda-fix-a-wrong-fixup-for-alc289-on-dell-machines.patch
queue-4.14/alsa-hda-realtek-fix-dock-line-out-volume-on-dell-precision-7520.patch
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2018-03-12 15:40 Patch "ALSA: seq: More protection for concurrent write and ioctl races" has been added to the 4.14-stable tree gregkh
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