From: Kevin Groeneveld Date: Sun, 6 Oct 2024 23:26:31 +0000 (-0400) Subject: usb: gadget: f_uac2: fix return value for UAC2_ATTRIBUTE_STRING store X-Git-Tag: v6.12-rc4~5^2~6 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9499327714de7bc5cf6c792112c1474932d8ad31;p=thirdparty%2Fkernel%2Flinux.git usb: gadget: f_uac2: fix return value for UAC2_ATTRIBUTE_STRING store The configfs store callback should return the number of bytes consumed not the total number of bytes we actually stored. These could differ if for example the passed in string had a newline we did not store. If the returned value does not match the number of bytes written the writer might assume a failure or keep trying to write the remaining bytes. For example the following command will hang trying to write the final newline over and over again (tested on bash 2.05b): echo foo > function_name Fixes: 993a44fa85c1 ("usb: gadget: f_uac2: allow changing interface name via configfs") Cc: stable Signed-off-by: Kevin Groeneveld Link: https://lore.kernel.org/r/20241006232637.4267-1-kgroeneveld@lenbrook.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c index 1cdda44455b34..ce5b77f891902 100644 --- a/drivers/usb/gadget/function/f_uac2.c +++ b/drivers/usb/gadget/function/f_uac2.c @@ -2061,7 +2061,7 @@ static ssize_t f_uac2_opts_##name##_store(struct config_item *item, \ const char *page, size_t len) \ { \ struct f_uac2_opts *opts = to_f_uac2_opts(item); \ - int ret = 0; \ + int ret = len; \ \ mutex_lock(&opts->lock); \ if (opts->refcnt) { \ @@ -2072,8 +2072,8 @@ static ssize_t f_uac2_opts_##name##_store(struct config_item *item, \ if (len && page[len - 1] == '\n') \ len--; \ \ - ret = scnprintf(opts->name, min(sizeof(opts->name), len + 1), \ - "%s", page); \ + scnprintf(opts->name, min(sizeof(opts->name), len + 1), \ + "%s", page); \ \ end: \ mutex_unlock(&opts->lock); \