[PATCH v2] ALSA: intel_hdmi: Fix off-by-one error in __hdmi_lpe_audio_probe()

[PATCH v2] ALSA: intel_hdmi: Fix off-by-one error in __hdmi_lpe_audio_probe()

[Thorsten Blum]

In __hdmi_lpe_audio_probe(), strscpy() is incorrectly called with the
length of the source string (excluding the NUL terminator) rather than
the size of the destination buffer. This results in one character less
being copied from 'card->shortname' to 'pcm->name'.

Use the destination buffer size instead to ensure the card name is
copied correctly.

Cc: stable@vger.kernel.org
Fixes: 75b1a8f9d62e ("ALSA: Convert strlcpy to strscpy when return value is unused")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Changes in v2:
- Use three parameter variant of strscpy() for backporting as suggested
  by Sakari Ailus <sakari.ailus@linux.intel.com>
- Link to v1: https://lore.kernel.org/lkml/20250805190809.31150-1-thorsten.blum@linux.dev/
---
 sound/x86/intel_hdmi_audio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c
index cc54539c6030..01f49555c5f6 100644
--- a/sound/x86/intel_hdmi_audio.c
+++ b/sound/x86/intel_hdmi_audio.c
@@ -1765,7 +1765,7 @@ static int __hdmi_lpe_audio_probe(struct platform_device *pdev)
 		/* setup private data which can be retrieved when required */
 		pcm->private_data = ctx;
 		pcm->info_flags = 0;
-		strscpy(pcm->name, card->shortname, strlen(card->shortname));
+		strscpy(pcm->name, card->shortname, sizeof(pcm->name));
 		/* setup the ops for playback */
 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &had_pcm_ops);
 
-- 
2.50.1

Re: [PATCH v2] ALSA: intel_hdmi: Fix off-by-one error in __hdmi_lpe_audio_probe()

[Takashi Iwai]

On Wed, 06 Aug 2025 01:41:53 +0200,
Thorsten Blum wrote:
> 
> In __hdmi_lpe_audio_probe(), strscpy() is incorrectly called with the
> length of the source string (excluding the NUL terminator) rather than
> the size of the destination buffer. This results in one character less
> being copied from 'card->shortname' to 'pcm->name'.
> 
> Use the destination buffer size instead to ensure the card name is
> copied correctly.
> 
> Cc: stable@vger.kernel.org
> Fixes: 75b1a8f9d62e ("ALSA: Convert strlcpy to strscpy when return value is unused")
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
> Changes in v2:
> - Use three parameter variant of strscpy() for backporting as suggested
>   by Sakari Ailus <sakari.ailus@linux.intel.com>
> - Link to v1: https://lore.kernel.org/lkml/20250805190809.31150-1-thorsten.blum@linux.dev/

Applied now.  Thanks.


Takashi