diff options
| author | Takashi Iwai <tiwai@suse.de> | 2010-04-13 13:33:54 +0400 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2010-04-13 14:01:14 +0400 |
| commit | d97e1b78239c7e7e441088e0b644bd3b076002e6 (patch) | |
| tree | b05b5085bea932662ce60061d5b4b93834683327 /sound/core/info.c | |
| parent | 24e4a1211f691fc671de44685430dbad757d8487 (diff) | |
| download | linux-d97e1b78239c7e7e441088e0b644bd3b076002e6.tar.xz | |
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.c | 14 |
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) |