This is a note to let you know that I've just added the patch titled
usb: gadget: f_uac2: validate input parameters
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-gadget-f_uac2-validate-input-parameters.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7bfa9df46acfc22c17e22bf935ad9c7d0d5f9354
Author: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
Date: Mon Mar 1 13:49:33 2021 +0200
usb: gadget: f_uac2: validate input parameters
[ Upstream commit 3713d5ceb04d5ab6a5e2b86dfca49170053f3a5e ]
Currently user can configure UAC2 function with
parameters that violate UAC2 spec or are not supported
by UAC2 gadget implementation.
This can lead to incorrect behavior if such gadget
is connected to the host - like enumeration failure
or other issues depending on host's UAC2 driver
implementation, bringing user to a long hours
of debugging the issue.
Instead of silently accept these parameters, throw
an error if they are not valid.
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
Link: https://lore.kernel.org/r/1614599375-8803-4-git-send-email-ruslan.bilovol@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index 6f03e944e0e3..dd960cea642f 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -14,6 +14,9 @@
#include "u_audio.h"
#include "u_uac2.h"
+/* UAC2 spec: 4.1 Audio Channel Cluster Descriptor */
+#define UAC2_CHANNEL_MASK 0x07FFFFFF
+
/*
* The driver implements a simple UAC_2 topology.
* USB-OUT -> IT_1 -> OT_3 -> ALSA_Capture
@@ -604,6 +607,36 @@ static void setup_descriptor(struct f_uac2_opts *opts)
hs_audio_desc[i] = NULL;
}
+static int afunc_validate_opts(struct g_audio *agdev, struct device *dev)
+{
+ struct f_uac2_opts *opts = g_audio_to_uac2_opts(agdev);
+
+ if (!opts->p_chmask && !opts->c_chmask) {
+ dev_err(dev, "Error: no playback and capture channels\n");
+ return -EINVAL;
+ } else if (opts->p_chmask & ~UAC2_CHANNEL_MASK) {
+ dev_err(dev, "Error: unsupported playback channels mask\n");
+ return -EINVAL;
+ } else if (opts->c_chmask & ~UAC2_CHANNEL_MASK) {
+ dev_err(dev, "Error: unsupported capture channels mask\n");
+ return -EINVAL;
+ } else if ((opts->p_ssize < 1) || (opts->p_ssize > 4)) {
+ dev_err(dev, "Error: incorrect playback sample size\n");
+ return -EINVAL;
+ } else if ((opts->c_ssize < 1) || (opts->c_ssize > 4)) {
+ dev_err(dev, "Error: incorrect capture sample size\n");
+ return -EINVAL;
+ } else if (!opts->p_srate) {
+ dev_err(dev, "Error: incorrect playback sampling rate\n");
+ return -EINVAL;
+ } else if (!opts->c_srate) {
+ dev_err(dev, "Error: incorrect capture sampling rate\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int
afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
{
@@ -612,11 +645,13 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
struct usb_composite_dev *cdev = cfg->cdev;
struct usb_gadget *gadget = cdev->gadget;
struct device *dev = &gadget->dev;
- struct f_uac2_opts *uac2_opts;
+ struct f_uac2_opts *uac2_opts = g_audio_to_uac2_opts(agdev);
struct usb_string *us;
int ret;
- uac2_opts = container_of(fn->fi, struct f_uac2_opts, func_inst);
+ ret = afunc_validate_opts(agdev, dev);
+ if (ret)
+ return ret;
us = usb_gstrings_attach(cdev, fn_strings, ARRAY_SIZE(strings_fn));
if (IS_ERR(us))
