Create seven control bits to allow the various restrictions for the anonymous file descriptor.
Signed-off-by: Jaroslav Kysela perex@perex.cz Reviewed-by: Takashi Iwai tiwai@suse.de --- include/sound/pcm.h | 1 + include/uapi/sound/asound.h | 9 +++++ sound/core/pcm_native.c | 93 ++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 102 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 bb14658e4482..57512f7131f2 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; @@ -2894,10 +2895,11 @@ static int snd_pcm_anonymous_dup(struct file *file, int fd, err, perm, flags; struct file *nfile; struct snd_pcm *pcm = substream->pcm; + struct snd_pcm_file *pcm_file;
if (get_user(perm, 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; @@ -2922,6 +2924,8 @@ 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, arg); return 0; } @@ -2933,6 +2937,73 @@ 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) @@ -2947,6 +3018,9 @@ 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; @@ -3108,6 +3182,8 @@ static ssize_t snd_pcm_read(struct file *file, char __user *buf, size_t count, substream = pcm_file->substream; if (PCM_RUNTIME_CHECK(substream)) return -ENXIO; + if (!(pcm_file->perm & SNDRV_PCM_PERM_RW)) + return -EPERM; runtime = substream->runtime; if (runtime->status->state == SNDRV_PCM_STATE_OPEN) return -EBADFD; @@ -3132,6 +3208,8 @@ static ssize_t snd_pcm_write(struct file *file, const char __user *buf, substream = pcm_file->substream; if (PCM_RUNTIME_CHECK(substream)) return -ENXIO; + if (!(pcm_file->perm & SNDRV_PCM_PERM_RW)) + return -EPERM; runtime = substream->runtime; if (runtime->status->state == SNDRV_PCM_STATE_OPEN) return -EBADFD; @@ -3158,6 +3236,8 @@ static ssize_t snd_pcm_readv(struct kiocb *iocb, struct iov_iter *to) substream = pcm_file->substream; if (PCM_RUNTIME_CHECK(substream)) return -ENXIO; + if (!(pcm_file->perm & SNDRV_PCM_PERM_RW)) + return -EPERM; runtime = substream->runtime; if (runtime->status->state == SNDRV_PCM_STATE_OPEN) return -EBADFD; @@ -3194,6 +3274,8 @@ static ssize_t snd_pcm_writev(struct kiocb *iocb, struct iov_iter *from) substream = pcm_file->substream; if (PCM_RUNTIME_CHECK(substream)) return -ENXIO; + if (!(pcm_file->perm & SNDRV_PCM_PERM_RW)) + return -EPERM; runtime = substream->runtime; if (runtime->status->state == SNDRV_PCM_STATE_OPEN) return -EBADFD; @@ -3295,6 +3377,9 @@ 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; @@ -3331,6 +3416,9 @@ 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; @@ -3505,11 +3593,14 @@ 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;