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authorTakashi Iwai <tiwai@suse.de>2010-04-13 11:33:54 +0200
committerTakashi Iwai <tiwai@suse.de>2010-04-13 12:01:14 +0200
commitd97e1b78239c7e7e441088e0b644bd3b076002e6 (patch)
treeb05b5085bea932662ce60061d5b4b93834683327 /sound/core/info.c
parent24e4a1211f691fc671de44685430dbad757d8487 (diff)
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>
Diffstat (limited to 'sound/core/info.c')
-rw-r--r--sound/core/info.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/sound/core/info.c b/sound/core/info.c
index ff968be81678..f90a6fd43fb4 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -232,10 +232,15 @@ static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
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 @@ static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer
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)