mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-18 08:28:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

ALSA: pcm: Fix unlocked state reads in read/write file ops

Browse Source 
The PCM read/write and readv/writev file operations reject streams in
OPEN or DISCONNECTED state before accessing the configured runtime
parameters. However, each operation reads runtime->state without the
PCM stream lock.

PCM state updates are serialized by the stream lock and may occur
concurrently from IRQ context. Use a local predicate based on
snd_pcm_get_state() to take a locked state snapshot for these VFS entry
checks.

This also consolidates the duplicated OPEN and DISCONNECTED tests. The
conditions and returned errors remain unchanged.

Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260610-alsa-pcm-read-write-state-helper-v1-1-93b7b992db09@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Cássio Gabriel
2026-06-10 08:31:30 -03:00
committed by Takashi Iwai
parent 764e7ed16d
commit 7bc02ab446
1 changed files with 12 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
sound/core/pcm_native.c
View File

@@ -645,6 +645,14 @@ snd_pcm_state_t snd_pcm_get_state(struct snd_pcm_substream *substream)
}
EXPORT_SYMBOL_GPL(snd_pcm_get_state);
static bool snd_pcm_state_open_or_disconnected(struct snd_pcm_substream *substream)
{
snd_pcm_state_t state = snd_pcm_get_state(substream);
return state == SNDRV_PCM_STATE_OPEN ||
state == SNDRV_PCM_STATE_DISCONNECTED;
}
static inline void snd_pcm_timer_notify(struct snd_pcm_substream *substream,
int event)
{
@@ -3569,8 +3577,7 @@ static ssize_t snd_pcm_read(struct file *file, char __user *buf, size_t count,
if (PCM_RUNTIME_CHECK(substream))
return -ENXIO;
runtime = substream->runtime;
if (runtime->state == SNDRV_PCM_STATE_OPEN ||
runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
if (snd_pcm_state_open_or_disconnected(substream))
return -EBADFD;
if (!frame_aligned(runtime, count))
return -EINVAL;
@@ -3594,8 +3601,7 @@ static ssize_t snd_pcm_write(struct file *file, const char __user *buf,
if (PCM_RUNTIME_CHECK(substream))
return -ENXIO;
runtime = substream->runtime;
if (runtime->state == SNDRV_PCM_STATE_OPEN ||
runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
if (snd_pcm_state_open_or_disconnected(substream))
return -EBADFD;
if (!frame_aligned(runtime, count))
return -EINVAL;
@@ -3621,8 +3627,7 @@ static ssize_t snd_pcm_readv(struct kiocb *iocb, struct iov_iter *to)
if (PCM_RUNTIME_CHECK(substream))
return -ENXIO;
runtime = substream->runtime;
if (runtime->state == SNDRV_PCM_STATE_OPEN ||
runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
if (snd_pcm_state_open_or_disconnected(substream))
return -EBADFD;
if (!user_backed_iter(to))
return -EINVAL;
@@ -3661,8 +3666,7 @@ static ssize_t snd_pcm_writev(struct kiocb *iocb, struct iov_iter *from)
if (PCM_RUNTIME_CHECK(substream))
return -ENXIO;
runtime = substream->runtime;
if (runtime->state == SNDRV_PCM_STATE_OPEN ||
runtime->state == SNDRV_PCM_STATE_DISCONNECTED)
if (snd_pcm_state_open_or_disconnected(substream))
return -EBADFD;
if (!user_backed_iter(from))
return -EINVAL;