From d97e1b78239c7e7e441088e0b644bd3b076002e6 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 13 Apr 2010 11:33:54 +0200 Subject: 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 --- sound/core/info.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'sound/core') 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 @@ 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) -- cgit v1.1