2023-10-30 20:41:07

by Justin Stitt

[permalink] [raw]
Subject: [PATCH] scsi: ibmvscsi: replace deprecated strncpy with strscpy

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

We expect partition_name to be NUL-terminated based on its usage with
format strings:
| dev_info(hostdata->dev, "host srp version: %s, "
| "host partition %s (%d), OS %d, max io %u\n",
| hostdata->madapter_info.srp_version,
| hostdata->madapter_info.partition_name,
| be32_to_cpu(hostdata->madapter_info.partition_number),
| be32_to_cpu(hostdata->madapter_info.os_type),
| be32_to_cpu(hostdata->madapter_info.port_max_txu[0]));
...
| len = snprintf(buf, PAGE_SIZE, "%s\n",
| hostdata->madapter_info.partition_name);

Moreover, NUL-padding is not required as madapter_info is explicitly
memset to 0:
| memset(&hostdata->madapter_info, 0x00,
| sizeof(hostdata->madapter_info));

Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
---
Note: build-tested only.

Found with: $ rg "strncpy\("
---
drivers/scsi/ibmvscsi/ibmvscsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 59599299615d..71f3e9563520 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -266,7 +266,7 @@ static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);

- strncpy(hostdata->madapter_info.partition_name, partition_name,
+ strscpy(hostdata->madapter_info.partition_name, partition_name,
sizeof(hostdata->madapter_info.partition_name));

hostdata->madapter_info.partition_number =

---
base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa
change-id: 20231030-strncpy-drivers-scsi-ibmvscsi-ibmvscsi-c-3b5019ce50ad

Best regards,
--
Justin Stitt <[email protected]>


2023-11-30 21:13:46

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] scsi: ibmvscsi: replace deprecated strncpy with strscpy

On Mon, Oct 30, 2023 at 08:40:48PM +0000, Justin Stitt wrote:
> strncpy() is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> We expect partition_name to be NUL-terminated based on its usage with
> format strings:
> | dev_info(hostdata->dev, "host srp version: %s, "
> | "host partition %s (%d), OS %d, max io %u\n",
> | hostdata->madapter_info.srp_version,
> | hostdata->madapter_info.partition_name,
> | be32_to_cpu(hostdata->madapter_info.partition_number),
> | be32_to_cpu(hostdata->madapter_info.os_type),
> | be32_to_cpu(hostdata->madapter_info.port_max_txu[0]));
> ...
> | len = snprintf(buf, PAGE_SIZE, "%s\n",
> | hostdata->madapter_info.partition_name);
>
> Moreover, NUL-padding is not required as madapter_info is explicitly
> memset to 0:
> | memset(&hostdata->madapter_info, 0x00,
> | sizeof(hostdata->madapter_info));
>
> Considering the above, a suitable replacement is `strscpy` [2] due to
> the fact that it guarantees NUL-termination on the destination buffer
> without unnecessarily NUL-padding.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>

Agreed; this conversion looks correct to me too.

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2023-12-01 09:41:34

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH] scsi: ibmvscsi: replace deprecated strncpy with strscpy

Justin Stitt <[email protected]> writes:
> strncpy() is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> We expect partition_name to be NUL-terminated based on its usage with
> format strings:
> | dev_info(hostdata->dev, "host srp version: %s, "
> | "host partition %s (%d), OS %d, max io %u\n",
> | hostdata->madapter_info.srp_version,
> | hostdata->madapter_info.partition_name,
> | be32_to_cpu(hostdata->madapter_info.partition_number),
> | be32_to_cpu(hostdata->madapter_info.os_type),
> | be32_to_cpu(hostdata->madapter_info.port_max_txu[0]));
> ...
> | len = snprintf(buf, PAGE_SIZE, "%s\n",
> | hostdata->madapter_info.partition_name);
>
> Moreover, NUL-padding is not required as madapter_info is explicitly
> memset to 0:
> | memset(&hostdata->madapter_info, 0x00,
> | sizeof(hostdata->madapter_info));
>
> Considering the above, a suitable replacement is `strscpy` [2] due to
> the fact that it guarantees NUL-termination on the destination buffer
> without unnecessarily NUL-padding.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>
> ---
> Note: build-tested only.

I gave it a quick boot, no issues.

Tested-by: Michael Ellerman <[email protected]> (powerpc)

cheers

2023-12-06 01:58:28

by Martin K. Petersen

[permalink] [raw]
Subject: Re: [PATCH] scsi: ibmvscsi: replace deprecated strncpy with strscpy


Michael,

>> strncpy() is deprecated for use on NUL-terminated destination strings
>> [1] and as such we should prefer more robust and less ambiguous string
>> interfaces.

> I gave it a quick boot, no issues.
>
> Tested-by: Michael Ellerman <[email protected]> (powerpc)

Applied to 6.8/scsi-staging, thanks!

--
Martin K. Petersen Oracle Linux Engineering

2023-12-14 04:31:05

by Martin K. Petersen

[permalink] [raw]
Subject: Re: [PATCH] scsi: ibmvscsi: replace deprecated strncpy with strscpy

On Mon, 30 Oct 2023 20:40:48 +0000, Justin Stitt wrote:

> strncpy() is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> We expect partition_name to be NUL-terminated based on its usage with
> format strings:
> | dev_info(hostdata->dev, "host srp version: %s, "
> | "host partition %s (%d), OS %d, max io %u\n",
> | hostdata->madapter_info.srp_version,
> | hostdata->madapter_info.partition_name,
> | be32_to_cpu(hostdata->madapter_info.partition_number),
> | be32_to_cpu(hostdata->madapter_info.os_type),
> | be32_to_cpu(hostdata->madapter_info.port_max_txu[0]));
> ...
> | len = snprintf(buf, PAGE_SIZE, "%s\n",
> | hostdata->madapter_info.partition_name);
>
> [...]

Applied to 6.8/scsi-queue, thanks!

[1/1] scsi: ibmvscsi: replace deprecated strncpy with strscpy
https://git.kernel.org/mkp/scsi/c/712b3f43ba0e

--
Martin K. Petersen Oracle Linux Engineering