[PATCH] scsi: libfcoe: Replace all non-returning strlcpy with strscpy

[PATCH] scsi: libfcoe: Replace all non-returning strlcpy with strscpy

[Azeem Shaikh]

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().
No return values were used, so direct replacement is safe.

[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>
---
 drivers/scsi/fcoe/fcoe_transport.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/fcoe/fcoe_transport.c b/drivers/scsi/fcoe/fcoe_transport.c
index 46b0bf237be1..a48d24af9ac3 100644
--- a/drivers/scsi/fcoe/fcoe_transport.c
+++ b/drivers/scsi/fcoe/fcoe_transport.c
@@ -711,7 +711,7 @@ static struct net_device *fcoe_if_to_netdev(const char *buffer)
 	char ifname[IFNAMSIZ + 2];
 
 	if (buffer) {
-		strlcpy(ifname, buffer, IFNAMSIZ);
+		strscpy(ifname, buffer, IFNAMSIZ);
 		cp = ifname + strlen(ifname);
 		while (--cp >= ifname && *cp == '\n')
 			*cp = '\0';

Re: [PATCH] scsi: libfcoe: Replace all non-returning strlcpy with strscpy

[Kees Cook]

On Tue, May 30, 2023 at 03:58:18PM +0000, Azeem Shaikh wrote:
> 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().
> No return values were used, so direct replacement is safe.
> 
> [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>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

Re: [PATCH] scsi: libfcoe: Replace all non-returning strlcpy with strscpy

[Martin K. Petersen]

Azeem,

> 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(). No return values were used, so direct replacement is
> safe.

Applied to 6.5/scsi-staging!

PS. It would help if you could submit changes like these as a series in
the future so I don't have to track each patch individually.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi: libfcoe: Replace all non-returning strlcpy with strscpy

[Azeem Shaikh]

On Wed, May 31, 2023 at 6:03 PM Martin K. Petersen
<martin.petersen@oracle.com> wrote:
>
>
> Azeem,
>
> > 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(). No return values were used, so direct replacement is
> > safe.
>
> Applied to 6.5/scsi-staging!

Thanks Martin!

>
> PS. It would help if you could submit changes like these as a series in
> the future so I don't have to track each patch individually.
>

Sure, I can do that.

Re: [PATCH] scsi: libfcoe: Replace all non-returning strlcpy with strscpy

[Martin K. Petersen]

On Tue, 30 May 2023 15:58:18 +0000, Azeem Shaikh wrote:

> 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().
> No return values were used, so direct replacement is safe.
> 
> [...]

Applied to 6.5/scsi-queue, thanks!

[1/1] scsi: libfcoe: Replace all non-returning strlcpy with strscpy
      https://git.kernel.org/mkp/scsi/c/4dae0262fb99

-- 
Martin K. Petersen	Oracle Linux Engineering