[PATCH 02/11] ALSA: pcm: Make mmap status read-only

[Takashi Iwai]

The mmap status record should be read-only.  Modifying it from
user-space may screw up things unexpectedly, so let's clear the write
bits at exposing it.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/core/pcm_native.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index d9485b1ab719..33769ca78cc8 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3668,6 +3668,7 @@ static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file
 	area->vm_ops = &snd_pcm_vm_ops_status;
 	area->vm_private_data = substream;
 	area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+	area->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
 	return 0;
 }
 
-- 
2.35.3