* [PATCH] usb: gadget: f_uac1_legacy: remove broken string configfs attributes
@ 2026-07-13 5:02 Xu Yang
2026-07-13 14:45 ` Frank Li
0 siblings, 1 reply; 2+ messages in thread
From: Xu Yang @ 2026-07-13 5:02 UTC (permalink / raw)
To: gregkh; +Cc: hataegu0826, kees, christophe.jaillet, linux-usb, linux-kernel,
imx
From: Xu Yang <xu.yang_2@nxp.com>
The UAC1_STR_ATTRIBUTE macro defines configfs show/store handlers for
the fn_play, fn_cap, and fn_cntl string options. The store function
contains an inverted null check on the kstrndup() return value.
This means every write attempt returns -ENOMEM on success and
dereferences a NULL pointer on allocation failure. The attributes
have been broken and unused for many years.
Remove the UAC1_STR_ATTRIBUTE macro and the three attributes it
generated. The internal defaults (FILE_PCM_PLAYBACK, FILE_PCM_CAPTURE,
FILE_CONTROL) set in f_audio_alloc_inst() are unaffected.
Fixes: 0854611a19ae ("usb: gadget: f_uac1: add configfs support")
Link: https://lore.kernel.org/linux-usb/20260625113154.1954813-1-xu.yang_2@oss.nxp.com/
Assisted-by: Claude:claude-sonnet-4.6
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
---
.../testing/configfs-usb-gadget-uac1_legacy | 3 --
drivers/usb/gadget/function/f_uac1_legacy.c | 50 -------------------
2 files changed, 53 deletions(-)
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy b/Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy
index b2eaefd9bc49..6a681d219f43 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy
@@ -5,8 +5,5 @@ Description:
The attributes:
audio_buf_size - audio buffer size
- fn_cap - capture pcm device file name
- fn_cntl - control device file name
- fn_play - playback pcm device file name
req_buf_size - ISO OUT endpoint request buffer size
req_count - ISO OUT endpoint request count
diff --git a/drivers/usb/gadget/function/f_uac1_legacy.c b/drivers/usb/gadget/function/f_uac1_legacy.c
index 5d201a2e30e7..b15f5e074f85 100644
--- a/drivers/usb/gadget/function/f_uac1_legacy.c
+++ b/drivers/usb/gadget/function/f_uac1_legacy.c
@@ -888,60 +888,10 @@ UAC1_INT_ATTRIBUTE(req_buf_size);
UAC1_INT_ATTRIBUTE(req_count);
UAC1_INT_ATTRIBUTE(audio_buf_size);
-#define UAC1_STR_ATTRIBUTE(name) \
-static ssize_t f_uac1_opts_##name##_show(struct config_item *item, \
- char *page) \
-{ \
- struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item); \
- int result; \
- \
- mutex_lock(&opts->lock); \
- result = sprintf(page, "%s\n", opts->name); \
- mutex_unlock(&opts->lock); \
- \
- return result; \
-} \
- \
-static ssize_t f_uac1_opts_##name##_store(struct config_item *item, \
- const char *page, size_t len) \
-{ \
- struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item); \
- int ret = -EBUSY; \
- char *tmp; \
- \
- mutex_lock(&opts->lock); \
- if (opts->refcnt) \
- goto end; \
- \
- tmp = kstrndup(page, len, GFP_KERNEL); \
- if (tmp) { \
- ret = -ENOMEM; \
- goto end; \
- } \
- if (opts->name##_alloc) \
- kfree(opts->name); \
- opts->name##_alloc = true; \
- opts->name = tmp; \
- ret = len; \
- \
-end: \
- mutex_unlock(&opts->lock); \
- return ret; \
-} \
- \
-CONFIGFS_ATTR(f_uac1_opts_, name)
-
-UAC1_STR_ATTRIBUTE(fn_play);
-UAC1_STR_ATTRIBUTE(fn_cap);
-UAC1_STR_ATTRIBUTE(fn_cntl);
-
static struct configfs_attribute *f_uac1_attrs[] = {
&f_uac1_opts_attr_req_buf_size,
&f_uac1_opts_attr_req_count,
&f_uac1_opts_attr_audio_buf_size,
- &f_uac1_opts_attr_fn_play,
- &f_uac1_opts_attr_fn_cap,
- &f_uac1_opts_attr_fn_cntl,
NULL,
};
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] usb: gadget: f_uac1_legacy: remove broken string configfs attributes
2026-07-13 5:02 [PATCH] usb: gadget: f_uac1_legacy: remove broken string configfs attributes Xu Yang
@ 2026-07-13 14:45 ` Frank Li
0 siblings, 0 replies; 2+ messages in thread
From: Frank Li @ 2026-07-13 14:45 UTC (permalink / raw)
To: Xu Yang
Cc: gregkh, hataegu0826, kees, christophe.jaillet, linux-usb,
linux-kernel, imx
On Mon, Jul 13, 2026 at 01:02:46PM +0800, Xu Yang wrote:
> From: Xu Yang <xu.yang_2@nxp.com>
>
> The UAC1_STR_ATTRIBUTE macro defines configfs show/store handlers for
> the fn_play, fn_cap, and fn_cntl string options. The store function
> contains an inverted null check on the kstrndup() return value.
>
> This means every write attempt returns -ENOMEM on success and
> dereferences a NULL pointer on allocation failure. The attributes
> have been broken and unused for many years.
>
> Remove the UAC1_STR_ATTRIBUTE macro and the three attributes it
> generated. The internal defaults (FILE_PCM_PLAYBACK, FILE_PCM_CAPTURE,
> FILE_CONTROL) set in f_audio_alloc_inst() are unaffected.
>
> Fixes: 0854611a19ae ("usb: gadget: f_uac1: add configfs support")
> Link: https://lore.kernel.org/linux-usb/20260625113154.1954813-1-xu.yang_2@oss.nxp.com/
> Assisted-by: Claude:claude-sonnet-4.6
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> ---
Reviewed-by: Frank Li <Frank.Li@nxp.com>
> .../testing/configfs-usb-gadget-uac1_legacy | 3 --
> drivers/usb/gadget/function/f_uac1_legacy.c | 50 -------------------
> 2 files changed, 53 deletions(-)
>
> diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy b/Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy
> index b2eaefd9bc49..6a681d219f43 100644
> --- a/Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy
> +++ b/Documentation/ABI/testing/configfs-usb-gadget-uac1_legacy
> @@ -5,8 +5,5 @@ Description:
> The attributes:
>
> audio_buf_size - audio buffer size
> - fn_cap - capture pcm device file name
> - fn_cntl - control device file name
> - fn_play - playback pcm device file name
> req_buf_size - ISO OUT endpoint request buffer size
> req_count - ISO OUT endpoint request count
> diff --git a/drivers/usb/gadget/function/f_uac1_legacy.c b/drivers/usb/gadget/function/f_uac1_legacy.c
> index 5d201a2e30e7..b15f5e074f85 100644
> --- a/drivers/usb/gadget/function/f_uac1_legacy.c
> +++ b/drivers/usb/gadget/function/f_uac1_legacy.c
> @@ -888,60 +888,10 @@ UAC1_INT_ATTRIBUTE(req_buf_size);
> UAC1_INT_ATTRIBUTE(req_count);
> UAC1_INT_ATTRIBUTE(audio_buf_size);
>
> -#define UAC1_STR_ATTRIBUTE(name) \
> -static ssize_t f_uac1_opts_##name##_show(struct config_item *item, \
> - char *page) \
> -{ \
> - struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item); \
> - int result; \
> - \
> - mutex_lock(&opts->lock); \
> - result = sprintf(page, "%s\n", opts->name); \
> - mutex_unlock(&opts->lock); \
> - \
> - return result; \
> -} \
> - \
> -static ssize_t f_uac1_opts_##name##_store(struct config_item *item, \
> - const char *page, size_t len) \
> -{ \
> - struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item); \
> - int ret = -EBUSY; \
> - char *tmp; \
> - \
> - mutex_lock(&opts->lock); \
> - if (opts->refcnt) \
> - goto end; \
> - \
> - tmp = kstrndup(page, len, GFP_KERNEL); \
> - if (tmp) { \
> - ret = -ENOMEM; \
> - goto end; \
> - } \
> - if (opts->name##_alloc) \
> - kfree(opts->name); \
> - opts->name##_alloc = true; \
> - opts->name = tmp; \
> - ret = len; \
> - \
> -end: \
> - mutex_unlock(&opts->lock); \
> - return ret; \
> -} \
> - \
> -CONFIGFS_ATTR(f_uac1_opts_, name)
> -
> -UAC1_STR_ATTRIBUTE(fn_play);
> -UAC1_STR_ATTRIBUTE(fn_cap);
> -UAC1_STR_ATTRIBUTE(fn_cntl);
> -
> static struct configfs_attribute *f_uac1_attrs[] = {
> &f_uac1_opts_attr_req_buf_size,
> &f_uac1_opts_attr_req_count,
> &f_uac1_opts_attr_audio_buf_size,
> - &f_uac1_opts_attr_fn_play,
> - &f_uac1_opts_attr_fn_cap,
> - &f_uac1_opts_attr_fn_cntl,
> NULL,
> };
>
> --
> 2.34.1
>
>
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