ALSA: pcm: Add more disconnection checks at file ops

In the case of hot-disconnection of a PCM device, all file operations
except for close should be rejected.  This patch adds more sanity
checks in the file operation code paths.

Link: https://lore.kernel.org/r/20211006142214.3089-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index d233cb3..46c643d 100644 (file)
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3218,6 +3218,9 @@ static int snd_pcm_common_ioctl(struct file *file,
        if (PCM_RUNTIME_CHECK(substream))
                return -ENXIO;
 
+       if (substream->runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
+               return -EBADFD;
+
        res = snd_power_wait(substream->pcm->card);
        if (res < 0)
                return res;
@@ -3344,6 +3347,9 @@ int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream,
        snd_pcm_uframes_t *frames = arg;
        snd_pcm_sframes_t result;
        
+       if (substream->runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
+               return -EBADFD;
+
        switch (cmd) {
        case SNDRV_PCM_IOCTL_FORWARD:
        {
@@ -3386,7 +3392,8 @@ 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->status->state == SNDRV_PCM_STATE_OPEN)
+       if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
+           runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
                return -EBADFD;
        if (!frame_aligned(runtime, count))
                return -EINVAL;
@@ -3410,7 +3417,8 @@ 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->status->state == SNDRV_PCM_STATE_OPEN)
+       if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
+           runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
                return -EBADFD;
        if (!frame_aligned(runtime, count))
                return -EINVAL;
@@ -3436,7 +3444,8 @@ 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->status->state == SNDRV_PCM_STATE_OPEN)
+       if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
+           runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
                return -EBADFD;
        if (!iter_is_iovec(to))
                return -EINVAL;
@@ -3472,7 +3481,8 @@ 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->status->state == SNDRV_PCM_STATE_OPEN)
+       if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
+           runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
                return -EBADFD;
        if (!iter_is_iovec(from))
                return -EINVAL;
@@ -3511,6 +3521,9 @@ static __poll_t snd_pcm_poll(struct file *file, poll_table *wait)
                return ok | EPOLLERR;
 
        runtime = substream->runtime;
+       if (runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
+               return ok | EPOLLERR;
+
        poll_wait(file, &runtime->sleep, wait);
 
        mask = 0;
@@ -3820,6 +3833,8 @@ static int snd_pcm_mmap(struct file *file, struct vm_area_struct *area)
        substream = pcm_file->substream;
        if (PCM_RUNTIME_CHECK(substream))
                return -ENXIO;
+       if (substream->runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
+               return -EBADFD;
 
        offset = area->vm_pgoff << PAGE_SHIFT;
        switch (offset) {
@@ -3856,6 +3871,8 @@ static int snd_pcm_fasync(int fd, struct file * file, int on)
        if (PCM_RUNTIME_CHECK(substream))
                return -ENXIO;
        runtime = substream->runtime;
+       if (runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
+               return -EBADFD;
        return fasync_helper(fd, file, on, &runtime->fasync);
 }