2023-11-16 19:14:21

by Kees Cook

Subject: [PATCH] parisc: Replace strlcpy() with strscpy()

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].
Additionally, it returns the size of the source string, not the
resulting size of the destination string. In an effort to remove strlcpy()
completely[2], replace strlcpy() here with strscpy().

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1]
Link: https://github.com/KSPP/linux/issues/89 [2]
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Azeem Shaikh <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
arch/parisc/kernel/processor.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
index 29e2750f86a4..e95a977ba5f3 100644
--- a/arch/parisc/kernel/processor.c
+++ b/arch/parisc/kernel/processor.c
@@ -383,7 +383,7 @@ show_cpuinfo (struct seq_file *m, void *v)
char cpu_name[60], *p;

/* strip PA path from CPU name to not confuse lscpu */
- strlcpy(cpu_name, per_cpu(cpu_data, 0).dev->name, sizeof(cpu_name));
+ strscpy(cpu_name, per_cpu(cpu_data, 0).dev->name, sizeof(cpu_name));
p = strrchr(cpu_name, '[');
if (p)
*(--p) = 0;
--
2.34.1

2023-11-17 14:48:47

by Helge Deller

Subject: Re: [PATCH] parisc: Replace strlcpy() with strscpy()

On 11/16/23 20:13, Kees Cook 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].
> Additionally, it returns the size of the source string, not the
> resulting size of the destination string. In an effort to remove strlcpy()
> completely[2], replace strlcpy() here with strscpy().
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1]
> Link: https://github.com/KSPP/linux/issues/89 [2]
> Cc: "James E.J. Bottomley" <[email protected]>
> Cc: Helge Deller <[email protected]>
> Cc: Azeem Shaikh <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

applied.

Thanks!
Helge

> ---
> arch/parisc/kernel/processor.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
> index 29e2750f86a4..e95a977ba5f3 100644
> --- a/arch/parisc/kernel/processor.c
> +++ b/arch/parisc/kernel/processor.c
> @@ -383,7 +383,7 @@ show_cpuinfo (struct seq_file *m, void *v)
> char cpu_name[60], *p;
>
> /* strip PA path from CPU name to not confuse lscpu */
> - strlcpy(cpu_name, per_cpu(cpu_data, 0).dev->name, sizeof(cpu_name));
> + strscpy(cpu_name, per_cpu(cpu_data, 0).dev->name, sizeof(cpu_name));
> p = strrchr(cpu_name, '[');
> if (p)
> *(--p) = 0;