In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: configfs: fix out-of-bounds read of qw_sign
os_desc_qw_sign_show() passes OS_STRING_QW_SIGN_LEN as the input
length to utf16s_to_utf8s(), but that argument counts UTF-16 code
units while OS_STRING_QW_SIGN_LEN (14) is the byte size of qw_sign[].
The array holds only OS_STRING_QW_SIGN_LEN / 2 (7) code units, so the
conversion reads up to 7 units (14 bytes) past the end of qw_sign[]
into the following members of struct gadget_info when the stored
signature fills the array without a NUL terminator, exposing those
bytes through the configfs attribute.
The store path halves the count for its input bound but passes the
full byte count as the utf8s_to_utf16s() output limit; use the
destination code-unit count in both directions.
