[PATCH 4.9 066/101] ALSA: info: Fix llseek return value when using callback

From: Greg Kroah-Hartman
Date: Tue Aug 23 2022 - 04:28:20 EST


From: Amadeusz Sławiński <amadeuszx.slawinski@xxxxxxxxxxxxxxx>

commit 9be080edcca330be4af06b19916c35227891e8bc upstream.

When using callback there was a flow of

ret = -EINVAL
if (callback) {
offset = callback();
goto out;
}
...
offset = some other value in case of no callback;
ret = offset;
out:
return ret;

which causes the snd_info_entry_llseek() to return -EINVAL when there is
callback handler. Fix this by setting "ret" directly to callback return
value before jumping to "out".

Fixes: 73029e0ff18d ("ALSA: info - Implement common llseek for binary mode")
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220817124924.3974577-1-amadeuszx.slawinski@xxxxxxxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/core/info.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -127,9 +127,9 @@ static loff_t snd_info_entry_llseek(stru
entry = data->entry;
mutex_lock(&entry->access);
if (entry->c.ops->llseek) {
- offset = entry->c.ops->llseek(entry,
- data->file_private_data,
- file, offset, orig);
+ ret = entry->c.ops->llseek(entry,
+ data->file_private_data,
+ file, offset, orig);
goto out;
}