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@xxxxxxxxx> --- v2: * Use "< 1" instead of "== -E2BIG". * Update commit log to say PAGE_SIZE instead of sizeof(dest). v1: * https://lore.kernel.org/all/20230613004341.3540325-1-azeemshaikh38@xxxxxxxxx/ drivers/usb/gadget/function/f_printer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c index 28db3e336e7d..b91425611969 100644 --- a/drivers/usb/gadget/function/f_printer.c +++ b/drivers/usb/gadget/function/f_printer.c @@ -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'; -- 2.41.0.162.gfafddb0af9-goog
