diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2020-03-19 18:08:59 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-04-26 09:33:49 -0400 |
| commit | ebe6976d3634a311367f72c2402f148ab9f23920 (patch) | |
| tree | 3c45f161f86ae3fc4c8102c2696295a608033222 | |
| parent | a656d47a010b74e390c4336efc0f617886ab407c (diff) | |
| download | linux-ebe6976d3634a311367f72c2402f148ab9f23920.tar.bz2 | |
pcm_native: result of put_user() needs to be checked
... and no, __put_user() doesn't help here - skipping
access_ok() on the second call does not remove the
possibility of page having become unmapped or r/o
in the meanwhile
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | sound/core/pcm_native.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index aef860256278..47838f57a647 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3093,7 +3093,8 @@ static int snd_pcm_xferi_frames_ioctl(struct snd_pcm_substream *substream, result = snd_pcm_lib_write(substream, xferi.buf, xferi.frames); else result = snd_pcm_lib_read(substream, xferi.buf, xferi.frames); - __put_user(result, &_xferi->result); + if (put_user(result, &_xferi->result)) + return -EFAULT; return result < 0 ? result : 0; } @@ -3122,7 +3123,8 @@ static int snd_pcm_xfern_frames_ioctl(struct snd_pcm_substream *substream, else result = snd_pcm_lib_readv(substream, bufs, xfern.frames); kfree(bufs); - __put_user(result, &_xfern->result); + if (put_user(result, &_xfern->result)) + return -EFAULT; return result < 0 ? result : 0; } @@ -3137,7 +3139,8 @@ static int snd_pcm_rewind_ioctl(struct snd_pcm_substream *substream, if (put_user(0, _frames)) return -EFAULT; result = snd_pcm_rewind(substream, frames); - __put_user(result, _frames); + if (put_user(result, _frames)) + return -EFAULT; return result < 0 ? result : 0; } @@ -3152,7 +3155,8 @@ static int snd_pcm_forward_ioctl(struct snd_pcm_substream *substream, if (put_user(0, _frames)) return -EFAULT; result = snd_pcm_forward(substream, frames); - __put_user(result, _frames); + if (put_user(result, _frames)) + return -EFAULT; return result < 0 ? result : 0; } |