From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Valentina Manea <valentina.manea.m@gmail.com>,
Shuah Khan <shuah@kernel.org>,
Shuah Khan <skhan@linuxfoundation.org>,
Kees Cook <keescook@chromium.org>
Cc: linux-hardening@vger.kernel.org,
Azeem Shaikh <azeemshaikh38@gmail.com>,
Hongren Zheng <i@zenithal.me>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3] usbip: usbip_host: Replace strlcpy with strscpy
Date: Thu, 15 Jun 2023 18:05:04 +0000 [thread overview]
Message-ID: <20230615180504.401169-1-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 sizeof(dest).
[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>
---
v3:
* Removed declaration of @len to fix build failures in v2.
v2:
* https://lore.kernel.org/all/20230614141026.2113749-1-azeemshaikh38@gmail.com/
* Use "< 0" instead of "== -E2BIG".
v1:
* https://lore.kernel.org/all/20230613004402.3540432-1-azeemshaikh38@gmail.com/
drivers/usb/usbip/stub_main.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/usb/usbip/stub_main.c b/drivers/usb/usbip/stub_main.c
index e8c3131a8543..0a6624d37929 100644
--- a/drivers/usb/usbip/stub_main.c
+++ b/drivers/usb/usbip/stub_main.c
@@ -167,15 +167,13 @@ static ssize_t match_busid_show(struct device_driver *drv, char *buf)
static ssize_t match_busid_store(struct device_driver *dev, const char *buf,
size_t count)
{
- int len;
char busid[BUSID_SIZE];
if (count < 5)
return -EINVAL;
/* busid needs to include \0 termination */
- len = strlcpy(busid, buf + 4, BUSID_SIZE);
- if (sizeof(busid) <= len)
+ if (strscpy(busid, buf + 4, BUSID_SIZE) < 0)
return -EINVAL;
if (!strncmp(buf, "add ", 4)) {
--
2.41.0.162.gfafddb0af9-goog
next reply other threads:[~2023-06-15 18:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-15 18:05 Azeem Shaikh [this message]
2023-06-22 3:10 ` [PATCH v3] usbip: usbip_host: Replace strlcpy with strscpy Kees Cook
2023-06-22 15:30 ` Shuah Khan
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