usb: gadget: function: printer: Replace strlcpy with strscpy

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().

Direct replacement is safe here since return value of -errno
is used to check for truncation instead of PAGE_SIZE.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Link: https://lore.kernel.org/r/20230615180318.400639-1-azeemshaikh38@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Azeem Shaikh 2023-06-15 18:03:18 +00:00 committed by Greg Kroah-Hartman
parent 8be558dcff
commit ee400a1be1
1 changed files with 2 additions and 2 deletions

View File

@ -1211,8 +1211,8 @@ static ssize_t f_printer_opts_pnp_string_show(struct config_item *item,
if (!opts->pnp_string)
goto unlock;
result = strlcpy(page, opts->pnp_string, PAGE_SIZE);
if (result >= PAGE_SIZE) {
result = strscpy(page, opts->pnp_string, PAGE_SIZE);
if (result < 1) {
result = PAGE_SIZE;
} else if (page[result - 1] != '\n' && result + 1 < PAGE_SIZE) {
page[result++] = '\n';