From: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx> [ Upstream commit a59c68a6a3d1b18e2494f526eb19893a34fa6ec6 ] Currently user can configure UAC1 function with parameters that violate UAC1 spec or are not supported by UAC1 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 UAC1 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/1614599375-8803-5-git-send-email-ruslan.bilovol@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/usb/gadget/function/f_uac1.c | 43 ++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c index 3f4ee28e7896..edbb3b9a9709 100644 --- a/drivers/usb/gadget/function/f_uac1.c +++ b/drivers/usb/gadget/function/f_uac1.c @@ -23,6 +23,9 @@ #include "u_audio.h" #include "u_uac1.h" +/* UAC1 spec: 3.7.2.3 Audio Channel Cluster Format */ +#define UAC1_CHANNEL_MASK 0x0FFF + struct f_uac1 { struct g_audio g_audio; u8 ac_intf, as_in_intf, as_out_intf; @@ -34,6 +37,11 @@ static inline struct f_uac1 *func_to_uac1(struct usb_function *f) return container_of(f, struct f_uac1, g_audio.func); } +static inline struct f_uac1_opts *g_audio_to_uac1_opts(struct g_audio *audio) +{ + return container_of(audio->func.fi, struct f_uac1_opts, func_inst); +} + /* * DESCRIPTORS ... most are static, but strings and full * configuration descriptors are built on demand. @@ -509,11 +517,42 @@ static void f_audio_disable(struct usb_function *f) /*-------------------------------------------------------------------------*/ +static int f_audio_validate_opts(struct g_audio *audio, struct device *dev) +{ + struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio); + + if (!opts->p_chmask && !opts->c_chmask) { + dev_err(dev, "Error: no playback and capture channels\n"); + return -EINVAL; + } else if (opts->p_chmask & ~UAC1_CHANNEL_MASK) { + dev_err(dev, "Error: unsupported playback channels mask\n"); + return -EINVAL; + } else if (opts->c_chmask & ~UAC1_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; +} + /* audio function driver setup/binding */ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f) { struct usb_composite_dev *cdev = c->cdev; struct usb_gadget *gadget = cdev->gadget; + struct device *dev = &gadget->dev; struct f_uac1 *uac1 = func_to_uac1(f); struct g_audio *audio = func_to_g_audio(f); struct f_uac1_opts *audio_opts; @@ -523,6 +562,10 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f) int rate; int status; + status = f_audio_validate_opts(audio, dev); + if (status) + return status; + audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst); us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1)); -- 2.30.2
