[PATCH] sound: ua101: fix division by zero at probe
SeungJu Cheon <[email protected]>
| Newsgroups | dev.linux.lists.linux-kernel-mentees,org.kernel.vger.linux-kernel,org.kernel.vger.linux-sound,org.kernel.vger.stable |
|---|---|
| Message-ID | <[email protected]> |
Add a missing sanity check for bNrChannels in detect_usb_format()
to prevent a division by zero in playback_urb_complete() and
capture_urb_complete().
USB core does not validate class-specific descriptor fields such
as bNrChannels, so drivers must verify them before use. If a
device provides bNrChannels = 0, frame_bytes becomes zero and is
later used as a divisor in the URB completion handlers, leading
to a kernel crash.
Fixes: 63978ab3e3e9 ("sound: add Edirol UA-101 support")
Cc: [email protected]
Signed-off-by: SeungJu Cheon <[email protected]>
---
Testing:
- dummy_hcd + raw_gadget emulating a UA-101 with bNrChannels=0.
sound/usb/misc/ua101.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/sound/usb/misc/ua101.c b/sound/usb/misc/ua101.c
index 49b3dd8d827d..d129b42eb979 100644
--- a/sound/usb/misc/ua101.c
+++ b/sound/usb/misc/ua101.c
@@ -974,6 +974,13 @@ static int detect_usb_format(struct ua101 *ua)
ua->capture.channels = fmt_capture->bNrChannels;
ua->playback.channels = fmt_playback->bNrChannels;
+ if (!ua->capture.channels || !ua->playback.channels) {
+ dev_err(&ua->dev->dev,
+ "invalid channel count: capture %u, playback %u\n",
+ ua->capture.channels, ua->playback.channels);
+ return -EINVAL;
+ }
+
ua->capture.frame_bytes =
fmt_capture->bSubframeSize * ua->capture.channels;
ua->playback.frame_bytes =
--
2.52.0