ALSA: info - Check file position validity in common layer
Check the validity of the file position in the common info layer before
calling read or write callbacks in assumption that entry->size is set up
properly to indicate the max file size.
Removed the redundant checks from the callbacks as well.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/info.c b/sound/core/info.c
index ff968be..f90a6fd 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -232,10 +232,15 @@
return -EFAULT;
break;
case SNDRV_INFO_CONTENT_DATA:
- if (entry->c.ops->read)
+ if (pos >= entry->size)
+ return 0;
+ if (entry->c.ops->read) {
+ size = entry->size - pos;
+ size = min(count, size);
size = entry->c.ops->read(entry,
data->file_private_data,
- file, buffer, count, pos);
+ file, buffer, size, pos);
+ }
break;
}
if ((ssize_t) size > 0)
@@ -282,10 +287,13 @@
size = count;
break;
case SNDRV_INFO_CONTENT_DATA:
- if (entry->c.ops->write)
+ if (entry->c.ops->write && count > 0) {
+ size_t maxsize = entry->size - pos;
+ count = min(count, maxsize);
size = entry->c.ops->write(entry,
data->file_private_data,
file, buffer, count, pos);
+ }
break;
}
if ((ssize_t) size > 0)
