path: root/sound
diff options
authorTakashi Iwai <tiwai@suse.de>2016-10-30 22:13:19 +0100
committerTakashi Iwai <tiwai@suse.de>2016-11-08 14:37:26 +0100
commit6809cd682b82dfff47943850d1a8c714f971b5ca (patch)
tree343beda600798c0c06e10e49e3f8402a42a72413 /sound
parent027a9fe6835620422b6713892175716f3613dd9d (diff)
ALSA: info: Return error for invalid read/write
Currently the ALSA proc handler allows read or write even if the proc file were write-only or read-only. It's mostly harmless, does thing but allocating memory and ignores the input/output. But it doesn't tell user about the invalid use, and it's confusing and inconsistent in comparison with other proc files. This patch adds some sanity checks and let the proc handler returning an -EIO error when the invalid read/write is performed. Cc: <stable@vger.kernel.org> # v4.2+ Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
1 files changed, 5 insertions, 1 deletions
diff --git a/sound/core/info.c b/sound/core/info.c
index 291d6ed80d80..8ab72e0f5932 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -325,6 +325,8 @@ static ssize_t snd_info_text_entry_write(struct file *file,
size_t next;
int err = 0;
+ if (!entry->c.text.write)
+ return -EIO;
pos = *offset;
if (!valid_pos(pos, count))
return -EIO;
@@ -369,7 +371,9 @@ static int snd_info_seq_show(struct seq_file *seq, void *p)
struct snd_info_private_data *data = seq->private;
struct snd_info_entry *entry = data->entry;
- if (entry->c.text.read) {
+ if (!entry->c.text.read) {
+ return -EIO;
+ } else {
data->rbuffer->buffer = (char *)seq; /* XXX hack! */
entry->c.text.read(entry, data->rbuffer);