[lvc-project] [PATCH 5.10] ASoC: SOF: Intel: hda: Fix potential buffer overflow by snprintf()

[Alexandra Diupina]

From: Takashi Iwai <tiwai at suse.de>

commit 94c1ceb043c1a002de9649bb630c8e8347645982 upstream.

snprintf() returns the would-be-filled size when the string overflows
the given buffer size, hence using this value may result in the buffer
overflow (although it's unrealistic).

This patch replaces with a safer version, scnprintf() for papering
over such a potential issue.

Fixes: 29c8e4398f02 ("ASoC: SOF: Intel: hda: add extended rom status dump to error log")
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Link: https://lore.kernel.org/r/20220801165420.25978-4-tiwai@suse.de
Signed-off-by: Mark Brown <broonie at kernel.org>
Signed-off-by: Alexandra Diupina <adiupina at astralinux.ru>
---
Backport fix for CVE-2022-50050
 sound/soc/sof/intel/hda.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/sof/intel/hda.c b/sound/soc/sof/intel/hda.c
index b4cc72483137..1d879c2b81e1 100644
--- a/sound/soc/sof/intel/hda.c
+++ b/sound/soc/sof/intel/hda.c
@@ -437,7 +437,7 @@ static void hda_dsp_dump_ext_rom_status(struct snd_sof_dev *sdev)
 
 	for (i = 0; i < HDA_EXT_ROM_STATUS_SIZE; i++) {
 		value = snd_sof_dsp_read(sdev, HDA_DSP_BAR, HDA_DSP_SRAM_REG_ROM_STATUS + i * 0x4);
-		len += snprintf(msg + len, sizeof(msg) - len, " 0x%x", value);
+		len += scnprintf(msg + len, sizeof(msg) - len, " 0x%x", value);
 	}
 
 	sof_dev_dbg_or_err(sdev->dev, hda->boot_iteration == HDA_FW_BOOT_ATTEMPTS,
-- 
2.30.2