From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Kees Cook <keescook@chromium.org>
Cc: linux-hardening@vger.kernel.org,
Azeem Shaikh <azeemshaikh38@gmail.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Albert Briscoe <albertsbriscoe@gmail.com>,
Andrzej Pietrasiewicz <andrzej.p@collabora.com>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>
Subject: [PATCH v2] usb: gadget: function: printer: Replace strlcpy with strscpy
Date: Thu, 15 Jun 2023 18:03:18 +0000 [thread overview]
Message-ID: <20230615180318.400639-1-azeemshaikh38@gmail.com> (raw)
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>
---
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@gmail.com/
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
reply other threads:[~2023-06-15 18:03 UTC|newest]
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