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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Takashi Iwai <tiwai@suse.de>,
        Cezary Rojewski <cezary.rojewski@intel.com>,
        Mark Brown <broonie@kernel.org>
Subject: [PATCH 5.19 176/365] ASoC: Intel: avs: Fix potential buffer overflow by snprintf()
Date:   Tue, 23 Aug 2022 10:01:17 +0200
Message-Id: <20220823080125.576859163@linuxfoundation.org>
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From: Takashi Iwai <tiwai@suse.de>

commit ca3b7b9dc9bc1fa552f4697b7cccfa0258a44d00 upstream.

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

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

Fixes: f1b3b320bd65 ("ASoC: Intel: avs: Generic soc component driver")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20220801165420.25978-2-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 sound/soc/intel/avs/pcm.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/sound/soc/intel/avs/pcm.c
+++ b/sound/soc/intel/avs/pcm.c
@@ -636,8 +636,8 @@ static ssize_t topology_name_read(struct
 	char buf[64];
 	size_t len;
 
-	len = snprintf(buf, sizeof(buf), "%s/%s\n", component->driver->topology_name_prefix,
-		       mach->tplg_filename);
+	len = scnprintf(buf, sizeof(buf), "%s/%s\n", component->driver->topology_name_prefix,
+			mach->tplg_filename);
 
 	return simple_read_from_buffer(user_buf, count, ppos, buf, len);
 }