diff options
| author | Cássio Gabriel <cassiogabrielcontato@gmail.com> | 2026-06-10 08:31:30 -0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2026-06-10 16:28:48 +0200 |
| commit | 7bc02ab446d38d8d56c548abcb974dfd6fade147 (patch) | |
| tree | 0040f0eb4b53341d669b06d439306e4907e5638a | |
| parent | 764e7ed16d2d6a5948a9e8032b2ef7f77678a8ae (diff) | |
ALSA: pcm: Fix unlocked state reads in read/write file ops
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>
| -rw-r--r-- | sound/core/pcm_native.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index db4f5cb39088..7dc0060617f1 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -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; |