From ecc8a9502b3c878ddf5479d796c5677767452034 Mon Sep 17 00:00:00 2001 From: Kevin Groeneveld Date: Sun, 6 Oct 2024 19:26:31 -0400 Subject: [PATCH] usb: gadget: f_uac2: fix return value for UAC2_ATTRIBUTE_STRING store [ Upstream commit 9499327714de7bc5cf6c792112c1474932d8ad31 ] 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 Signed-off-by: Sasha Levin --- drivers/usb/gadget/function/f_uac2.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c index 79d1f87c6cc5..b3dc5f5164f4 100644 --- a/drivers/usb/gadget/function/f_uac2.c +++ b/drivers/usb/gadget/function/f_uac2.c @@ -2052,7 +2052,7 @@ 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) { \ @@ -2063,8 +2063,8 @@ 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); \