[PATCH] kdb: address -Wformat-security warnings

[PATCH] kdb: address -Wformat-security warnings

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

When -Wformat-security is not disabled, using a string pointer
as a format causes a warning:

kernel/debug/kdb/kdb_io.c: In function 'kdb_read':
kernel/debug/kdb/kdb_io.c:365:36: error: format not a string literal and no format arguments [-Werror=format-security]
  365 |                         kdb_printf(kdb_prompt_str);
      |                                    ^~~~~~~~~~~~~~
kernel/debug/kdb/kdb_io.c: In function 'kdb_getstr':
kernel/debug/kdb/kdb_io.c:456:20: error: format not a string literal and no format arguments [-Werror=format-security]
  456 |         kdb_printf(kdb_prompt_str);
      |                    ^~~~~~~~~~~~~~

Use an explcit "%s" format instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 kernel/debug/kdb/kdb_io.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 3131334d7a81..7da3fa7beffd 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -362,7 +362,7 @@ static char *kdb_read(char *buffer, size_t bufsize)
 			if (i >= dtab_count)
 				kdb_printf("...");
 			kdb_printf("\n");
-			kdb_printf(kdb_prompt_str);
+			kdb_printf("%s",  kdb_prompt_str);
 			kdb_printf("%s", buffer);
 			if (cp != lastchar)
 				kdb_position_cursor(kdb_prompt_str, buffer, cp);
@@ -453,7 +453,7 @@ char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
 {
 	if (prompt && kdb_prompt_str != prompt)
 		strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
-	kdb_printf(kdb_prompt_str);
+	kdb_printf("%s", kdb_prompt_str);
 	kdb_nextline = 1;	/* Prompt and input resets line number */
 	return kdb_read(buffer, bufsize);
 }
-- 
2.39.2

Re: [PATCH] kdb: address -Wformat-security warnings

[Doug Anderson]

Hi,

On Tue, May 28, 2024 at 5:12 AM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> When -Wformat-security is not disabled, using a string pointer
> as a format causes a warning:
>
> kernel/debug/kdb/kdb_io.c: In function 'kdb_read':
> kernel/debug/kdb/kdb_io.c:365:36: error: format not a string literal and no format arguments [-Werror=format-security]
>   365 |                         kdb_printf(kdb_prompt_str);
>       |                                    ^~~~~~~~~~~~~~
> kernel/debug/kdb/kdb_io.c: In function 'kdb_getstr':
> kernel/debug/kdb/kdb_io.c:456:20: error: format not a string literal and no format arguments [-Werror=format-security]
>   456 |         kdb_printf(kdb_prompt_str);
>       |                    ^~~~~~~~~~~~~~
>
> Use an explcit "%s" format instead.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  kernel/debug/kdb/kdb_io.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)")
Reviewed-by: Douglas Anderson <dianders@chromium.org>

...probably also justifies a:

Cc: stable@vger.kernel.org


-Doug

Re: [PATCH] kdb: address -Wformat-security warnings

[Daniel Thompson]

On Tue, 28 May 2024 14:11:48 +0200, Arnd Bergmann wrote:
> When -Wformat-security is not disabled, using a string pointer
> as a format causes a warning:
> 
> kernel/debug/kdb/kdb_io.c: In function 'kdb_read':
> kernel/debug/kdb/kdb_io.c:365:36: error: format not a string literal and no format arguments [-Werror=format-security]
>   365 |                         kdb_printf(kdb_prompt_str);
>       |                                    ^~~~~~~~~~~~~~
> kernel/debug/kdb/kdb_io.c: In function 'kdb_getstr':
> kernel/debug/kdb/kdb_io.c:456:20: error: format not a string literal and no format arguments [-Werror=format-security]
>   456 |         kdb_printf(kdb_prompt_str);
>       |                    ^~~~~~~~~~~~~~
> 
> [...]

Applied, thanks!

[1/1] kdb: address -Wformat-security warnings
      commit: 70867efacf4370b6c7cdfc7a5b11300e9ef7de64

Best regards,
-- 
Daniel Thompson <daniel.thompson@linaro.org>