On Thu, Apr 11, 2024 at 12:46:16PM -0400, Ivan Avdeev wrote:
> This commit fixes uvc gadget support on 32-bit platforms.
>
> Commit 0df28607c5cb ("usb: gadget: uvc: Generalise helper functions for
> reuse") introduced a helper function __uvcg_iter_item_entries() to aid
> with parsing lists of items on configfs attributes stores. This function
> is a generalization of another very similar function, which used a
> stack-allocated temporary buffer of fixed size for each item in the list
> and used the sizeof() operator to check for potential buffer overruns.
> The new function was changed to allocate the now variably sized temp
> buffer on heap, but wasn't properly updated to also check for max buffer
> size using the computed size instead of sizeof() operator.
>
> As a result, the maximum item size was 7 (plus null terminator) on
> 64-bit platforms, and 3 on 32-bit ones. While 7 is accidentally just
> barely enough, 3 is definitely too small for some of UVC configfs
> attributes. For example, dwFrameInteval, specified in 100ns units,
> usually has 6-digit item values, e.g. 166666 for 60fps.
>
> Fixes: 0df28607c5cb ("usb: gadget: uvc: Generalise helper functions for reuse")
> Signed-off-by: Ivan Avdeev <me@provod.works>
> ---
> drivers/usb/gadget/function/uvc_configfs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
> index 7e704b2bcfd1..a4377df612f5 100644
> --- a/drivers/usb/gadget/function/uvc_configfs.c
> +++ b/drivers/usb/gadget/function/uvc_configfs.c
> @@ -92,10 +92,10 @@ static int __uvcg_iter_item_entries(const char *page, size_t len,
>
> while (pg - page < len) {
> i = 0;
> - while (i < sizeof(buf) && (pg - page < len) &&
> + while (i < bufsize && (pg - page < len) &&
> *pg != '\0' && *pg != '\n')
> buf[i++] = *pg++;
> - if (i == sizeof(buf)) {
> + if (i == bufsize) {
> ret = -EINVAL;
> goto out_free_buf;
> }
>
> base-commit: 2c71fdf02a95b3dd425b42f28fd47fb2b1d22702
> --
> 2.43.2
>
>
Hi,
This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him
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