On Wed, 30 Jan 2019 09:47:33 +0100,
Jaroslav Kysela wrote:
>
> Create seven control bits to allow the various restrictions for the
> anonymous file descriptor.
>
> Signed-off-by: Jaroslav Kysela <perex@xxxxxxxx>
I think we need to check SNDRV_PCM_PERM_RW for read/write ops, too.
Other than that, looks good to me.
Reviewed-by: Takashi Iwai <tiwai@xxxxxxx>
thanks,
Takashi
> ---
> include/sound/pcm.h | 1 +
> include/uapi/sound/asound.h | 9 +++++
> sound/core/pcm_native.c | 85 ++++++++++++++++++++++++++++++++++++++++++++-
> 3 files changed, 94 insertions(+), 1 deletion(-)
>
> diff --git a/include/sound/pcm.h b/include/sound/pcm.h
> index b79ffaa0241d..e0469b2c1115 100644
> --- a/include/sound/pcm.h
> +++ b/include/sound/pcm.h
> @@ -227,6 +227,7 @@ struct snd_pcm_ops {
> struct snd_pcm_file {
> struct snd_pcm_substream *substream;
> int no_compat_mmap;
> + unsigned int perm; /* file descriptor permissions */
> unsigned int user_pversion; /* supported protocol version */
> };
>
> diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
> index ebc17d5a3490..8d99aa8916f0 100644
> --- a/include/uapi/sound/asound.h
> +++ b/include/uapi/sound/asound.h
> @@ -571,6 +571,15 @@ enum {
> #define SNDRV_CHMAP_PHASE_INVERSE (0x01 << 16)
> #define SNDRV_CHMAP_DRIVER_SPEC (0x02 << 16)
>
> +#define SNDRV_PCM_PERM_MMAP (1<<0)
> +#define SNDRV_PCM_PERM_MMAP_STATUS (1<<1)
> +#define SNDRV_PCM_PERM_MMAP_CONTROL (1<<2)
> +#define SNDRV_PCM_PERM_RW (1<<3)
> +#define SNDRV_PCM_PERM_CONTROL (1<<4)
> +#define SNDRV_PCM_PERM_STATUS (1<<5)
> +#define SNDRV_PCM_PERM_SYNC (1<<6)
> +#define SNDRV_PCM_PERM_MASK ((SNDRV_PCM_PERM_SYNC<<1)-1)
> +
> #define SNDRV_PCM_IOCTL_PVERSION _IOR('A', 0x00, int)
> #define SNDRV_PCM_IOCTL_INFO _IOR('A', 0x01, struct snd_pcm_info)
> #define SNDRV_PCM_IOCTL_TSTAMP _IOW('A', 0x02, int)
> diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
> index 8874a685f1e8..0fceed62b839 100644
> --- a/sound/core/pcm_native.c
> +++ b/sound/core/pcm_native.c
> @@ -2502,6 +2502,7 @@ static int snd_pcm_open_file(struct file *file,
> return -ENOMEM;
> }
> pcm_file->substream = substream;
> + pcm_file->perm = ~0;
> if (substream->ref_count == 1)
> substream->pcm_release = pcm_release_private;
> file->private_data = pcm_file;
> @@ -2897,10 +2898,11 @@ static int snd_pcm_anonymous_dup(struct file *file,
> int flags;
> struct file *nfile;
> struct snd_pcm *pcm = substream->pcm;
> + struct snd_pcm_file *pcm_file;
>
> if (get_user(perm, (int __user *)arg))
> return -EFAULT;
> - if (perm < 0)
> + if (perm & ~SNDRV_PCM_PERM_MASK)
> return -EPERM;
> flags = file->f_flags & (O_ACCMODE | O_NONBLOCK);
> flags |= O_APPEND | O_CLOEXEC;
> @@ -2925,6 +2927,8 @@ static int snd_pcm_anonymous_dup(struct file *file,
> err = snd_pcm_open_file(nfile, substream->pcm,
> substream->stream, substream->number);
> if (err >= 0) {
> + pcm_file = nfile->private_data;
> + pcm_file->perm = perm;
> put_user(fd, (int __user *)arg);
> return 0;
> }
> @@ -2936,6 +2940,73 @@ static int snd_pcm_anonymous_dup(struct file *file,
> return err;
> }
>
> +static int snd_pcm_ioctl_check_perm(struct snd_pcm_file *pcm_file,
> + unsigned int cmd)
> +{
> + if (pcm_file->perm == ~0)
> + return 1;
> + /*
> + * the setup, linking and anonymous dup is not allowed
> + * for the restricted file descriptors
> + */
> + switch (cmd) {
> + case SNDRV_PCM_IOCTL_PVERSION:
> + case SNDRV_PCM_IOCTL_INFO:
> + case SNDRV_PCM_IOCTL_USER_PVERSION:
> + case SNDRV_PCM_IOCTL_CHANNEL_INFO:
> + return 1;
> + }
> + if (pcm_file->perm & SNDRV_PCM_PERM_CONTROL) {
> + switch (cmd) {
> + case SNDRV_PCM_IOCTL_PREPARE:
> + case SNDRV_PCM_IOCTL_RESET:
> + case SNDRV_PCM_IOCTL_START:
> + case SNDRV_PCM_IOCTL_XRUN:
> + case SNDRV_PCM_IOCTL_RESUME:
> + case SNDRV_PCM_IOCTL_DRAIN:
> + case SNDRV_PCM_IOCTL_DROP:
> + case SNDRV_PCM_IOCTL_PAUSE:
> + return 1;
> + default:
> + break;
> + }
> + }
> + if (pcm_file->perm & SNDRV_PCM_PERM_STATUS) {
> + switch (cmd) {
> + case SNDRV_PCM_IOCTL_STATUS:
> + case SNDRV_PCM_IOCTL_STATUS_EXT:
> + case SNDRV_PCM_IOCTL_DELAY:
> + return 1;
> + default:
> + break;
> + }
> + }
> + if (pcm_file->perm & SNDRV_PCM_PERM_SYNC) {
> + switch (cmd) {
> + case SNDRV_PCM_IOCTL_HWSYNC:
> + case SNDRV_PCM_IOCTL_SYNC_PTR:
> + case SNDRV_PCM_IOCTL_REWIND:
> + case SNDRV_PCM_IOCTL_FORWARD:
> + return 1;
> + default:
> + break;
> + }
> + }
> + if (pcm_file->perm & SNDRV_PCM_PERM_RW) {
> + switch (cmd) {
> + case SNDRV_PCM_IOCTL_WRITEI_FRAMES:
> + case SNDRV_PCM_IOCTL_READI_FRAMES:
> + case SNDRV_PCM_IOCTL_WRITEN_FRAMES:
> + case SNDRV_PCM_IOCTL_READN_FRAMES:
> + return 1;
> + default:
> + break;
> + }
> + }
> +
> + return 0;
> +}
> +
> static int snd_pcm_common_ioctl(struct file *file,
> struct snd_pcm_substream *substream,
> unsigned int cmd, void __user *arg)
> @@ -2950,6 +3021,9 @@ static int snd_pcm_common_ioctl(struct file *file,
> if (res < 0)
> return res;
>
> + if (!snd_pcm_ioctl_check_perm(pcm_file, cmd))
> + return -EPERM;
> +
> switch (cmd) {
> case SNDRV_PCM_IOCTL_PVERSION:
> return put_user(SNDRV_PCM_VERSION, (int __user *)arg) ? -EFAULT : 0;
> @@ -3298,6 +3372,9 @@ static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file
> struct vm_area_struct *area)
> {
> long size;
> + struct snd_pcm_file *pcm_file = file->private_data;
> + if (!(pcm_file->perm & SNDRV_PCM_PERM_MMAP_STATUS))
> + return -EPERM;
> if (!(area->vm_flags & VM_READ))
> return -EINVAL;
> size = area->vm_end - area->vm_start;
> @@ -3334,6 +3411,9 @@ static int snd_pcm_mmap_control(struct snd_pcm_substream *substream, struct file
> struct vm_area_struct *area)
> {
> long size;
> + struct snd_pcm_file *pcm_file = file->private_data;
> + if (!(pcm_file->perm & SNDRV_PCM_PERM_MMAP_CONTROL))
> + return -EPERM;
> if (!(area->vm_flags & VM_READ))
> return -EINVAL;
> size = area->vm_end - area->vm_start;
> @@ -3508,11 +3588,14 @@ int snd_pcm_mmap_data(struct snd_pcm_substream *substream, struct file *file,
> struct vm_area_struct *area)
> {
> struct snd_pcm_runtime *runtime;
> + struct snd_pcm_file *pcm_file = file->private_data;
> long size;
> unsigned long offset;
> size_t dma_bytes;
> int err;
>
> + if (!(pcm_file->perm & SNDRV_PCM_PERM_MMAP))
> + return -EPERM;
> if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
> if (!(area->vm_flags & (VM_WRITE|VM_READ)))
> return -EINVAL;
> --
> 2.13.6
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>
o
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