2023-10-29 07:21:08

by Christophe JAILLET

Subject: [PATCH] riscv: Fix an off-by-one in get_early_cmdline()

The ending NULL is not taken into account by strncat(), so switch to
strlcat() to correctly compute the size of the available memory when
appending CONFIG_CMDLINE to 'early_cmdline'.

Fixes: 26e7aacb83df ("riscv: Allow to downgrade paging mode from the command line")
Signed-off-by: Christophe JAILLET <[email protected]>
---
arch/riscv/kernel/pi/cmdline_early.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/pi/cmdline_early.c b/arch/riscv/kernel/pi/cmdline_early.c
index 68e786c84c94..f6d4dedffb84 100644
--- a/arch/riscv/kernel/pi/cmdline_early.c
+++ b/arch/riscv/kernel/pi/cmdline_early.c
@@ -38,8 +38,7 @@ static char *get_early_cmdline(uintptr_t dtb_pa)
if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
fdt_cmdline_size == 0 /* CONFIG_CMDLINE_FALLBACK */) {
- strncat(early_cmdline, CONFIG_CMDLINE,
- COMMAND_LINE_SIZE - fdt_cmdline_size);
+ strlcat(early_cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
}

return early_cmdline;
--
2.34.1

2024-01-10 06:39:14

by Alexandre Ghiti

Subject: Re: [PATCH] riscv: Fix an off-by-one in get_early_cmdline()

Hi Christophe,

On 29/10/2023 08:20, Christophe JAILLET wrote:
> The ending NULL is not taken into account by strncat(), so switch to
> strlcat() to correctly compute the size of the available memory when
> appending CONFIG_CMDLINE to 'early_cmdline'.
>
> Fixes: 26e7aacb83df ("riscv: Allow to downgrade paging mode from the command line")
> Signed-off-by: Christophe JAILLET <[email protected]>
> ---
> arch/riscv/kernel/pi/cmdline_early.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kernel/pi/cmdline_early.c b/arch/riscv/kernel/pi/cmdline_early.c
> index 68e786c84c94..f6d4dedffb84 100644
> --- a/arch/riscv/kernel/pi/cmdline_early.c
> +++ b/arch/riscv/kernel/pi/cmdline_early.c
> @@ -38,8 +38,7 @@ static char *get_early_cmdline(uintptr_t dtb_pa)
> if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
> IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
> fdt_cmdline_size == 0 /* CONFIG_CMDLINE_FALLBACK */) {
> - strncat(early_cmdline, CONFIG_CMDLINE,
> - COMMAND_LINE_SIZE - fdt_cmdline_size);
> + strlcat(early_cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
> }
>
> return early_cmdline;

This looks good to me, you can add:

Reviewed-by: Alexandre Ghiti <[email protected]>

Thanks,

Alex

2024-01-12 06:31:34

by patchwork-bot+linux-riscv

Subject: Re: [PATCH] riscv: Fix an off-by-one in get_early_cmdline()

Hello:

This patch was applied to riscv/linux.git (for-next)
by Palmer Dabbelt <[email protected]>:

On Sun, 29 Oct 2023 08:20:40 +0100 you wrote:
> The ending NULL is not taken into account by strncat(), so switch to
> strlcat() to correctly compute the size of the available memory when
> appending CONFIG_CMDLINE to 'early_cmdline'.
>
> Fixes: 26e7aacb83df ("riscv: Allow to downgrade paging mode from the command line")
> Signed-off-by: Christophe JAILLET <[email protected]>
>
> [...]

Here is the summary with links:
- riscv: Fix an off-by-one in get_early_cmdline()
https://git.kernel.org/riscv/c/adb1f95d388a

You are awesome, thank you!
--
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