From 3b597d24dc0455ae926f1053f97c2725038fc3cd Mon Sep 17 00:00:00 2001 From: Guangshuo Li Date: Wed, 8 Jul 2026 19:36:25 +0800 Subject: [PATCH] ALSA: hda: cs35l41: validate and free ACPI mute object cs35l41_get_acpi_mute_state() evaluates a _DSM method to get the ACPI mute state and reads the first byte from the returned object. However, the returned ACPI object is owned by the caller and is never freed after use, so each successful query leaks the _DSM result object. The code also assumes that the returned object is a buffer with at least one byte. A malformed firmware response can return a different object type or an empty buffer, and the direct ret->buffer.pointer dereference can then access an invalid pointer. Use the typed _DSM helper, validate that the returned buffer contains at least one byte, and free the ACPI object after reading it. Fixes: 447106e92a0c ("ALSA: hda: cs35l41: Support mute notifications for CS35L41 HDA") Signed-off-by: Guangshuo Li Link: https://patch.msgid.link/20260708113625.752913-1-lgs201920130244@gmail.com Signed-off-by: Takashi Iwai --- sound/hda/codecs/side-codecs/cs35l41_hda.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/sound/hda/codecs/side-codecs/cs35l41_hda.c b/sound/hda/codecs/side-codecs/cs35l41_hda.c index 64a5bd895fd1..237059ef22f5 100644 --- a/sound/hda/codecs/side-codecs/cs35l41_hda.c +++ b/sound/hda/codecs/side-codecs/cs35l41_hda.c @@ -1434,10 +1434,19 @@ static int cs35l41_get_acpi_mute_state(struct cs35l41_hda *cs35l41, acpi_handle guid_parse(CS35L41_UUID, &guid); if (cs35l41_dsm_supported(handle, CS35L41_DSM_GET_MUTE)) { - ret = acpi_evaluate_dsm(handle, &guid, 0, CS35L41_DSM_GET_MUTE, NULL); + ret = acpi_evaluate_dsm_typed(handle, &guid, 0, + CS35L41_DSM_GET_MUTE, NULL, + ACPI_TYPE_BUFFER); + if (!ret) return -EINVAL; + if (!ret->buffer.length || !ret->buffer.pointer) { + ACPI_FREE(ret); + return -EINVAL; + } + mute = *ret->buffer.pointer; + ACPI_FREE(ret); dev_dbg(cs35l41->dev, "CS35L41_DSM_GET_MUTE: %d\n", mute); }