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

From: John Paul Adrian Glaubitz
Date: Wed Jun 14 2023 - 15:22:39 EST


On Tue, 2023-05-30 at 16:30 +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@xxxxxxxxx>
> ---
> arch/sh/drivers/dma/dma-api.c | 2 +-
> arch/sh/kernel/setup.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/sh/drivers/dma/dma-api.c b/arch/sh/drivers/dma/dma-api.c
> index ab9170494dcc..89cd4a3b4cca 100644
> --- a/arch/sh/drivers/dma/dma-api.c
> +++ b/arch/sh/drivers/dma/dma-api.c
> @@ -198,7 +198,7 @@ int request_dma(unsigned int chan, const char *dev_id)
> if (atomic_xchg(&channel->busy, 1))
> return -EBUSY;
>
> - strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
> + strscpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
>
> if (info->ops->request) {
> result = info->ops->request(channel);
> diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
> index af977ec4ca5e..e4f0f9a1d355 100644
> --- a/arch/sh/kernel/setup.c
> +++ b/arch/sh/kernel/setup.c
> @@ -304,9 +304,9 @@ void __init setup_arch(char **cmdline_p)
> bss_resource.end = virt_to_phys(__bss_stop)-1;
>
> #ifdef CONFIG_CMDLINE_OVERWRITE
> - strlcpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
> + strscpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
> #else
> - strlcpy(command_line, COMMAND_LINE, sizeof(command_line));
> + strscpy(command_line, COMMAND_LINE, sizeof(command_line));
> #ifdef CONFIG_CMDLINE_EXTEND
> strlcat(command_line, " ", sizeof(command_line));
> strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));

Acked-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>

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