6.6-stable review patch. If anyone has any objections, please let me know.
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From: John Keeping jkeeping@inmusicbrands.com
[ Upstream commit e60284b63245b84c3ae352427ed5ff8b79266b91 ]
Most writes to configfs handle an optional newline, but do not require it. By using the number of bytes written as the limit for scnprintf() it is guaranteed that the final character in the buffer will be overwritten.
This is expected if it is a newline but is undesirable when a string is written "as-is" (as libusbgx does, for example).
Update the store function to strip an optional newline, matching the behaviour of usb_string_copy().
Signed-off-by: John Keeping jkeeping@inmusicbrands.com Link: https://lore.kernel.org/r/20240708142553.3995022-1-jkeeping@inmusicbrands.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Stable-dep-of: 9499327714de ("usb: gadget: f_uac2: fix return value for UAC2_ATTRIBUTE_STRING store") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/gadget/function/f_uac2.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c index 55a4f07bc9cc1..79d1f87c6cc59 100644 --- a/drivers/usb/gadget/function/f_uac2.c +++ b/drivers/usb/gadget/function/f_uac2.c @@ -2060,7 +2060,10 @@ static ssize_t f_uac2_opts_##name##_store(struct config_item *item, \ goto end; \ } \ \ - ret = scnprintf(opts->name, min(sizeof(opts->name), len), \ + if (len && page[len - 1] == '\n') \ + len--; \ + \ + ret = scnprintf(opts->name, min(sizeof(opts->name), len + 1), \ "%s", page); \ \ end: \