From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793971481; b=Rz4z98zRXAz9B00cwkM4xw3KmsIbc7Q7pbv/KR26r7DfntXrcAVmlgbermeiRhxCCfq0 MjY9hPDpGO9ia6RnJai7BRrladssclH5ZmU/xmq4QrYHKz/POJJhlCja/9wSwxH2XPj5B j+hPmLrAKz4oyRmmi2hPR9sLAQ2qJLsTJ4B5w8BArQovvjmHrh2xm5CeEfYd8MiN3V59b 7VqPfMVWBV/EntjbidyA+jQqhH3Rr2y3+WvNY6hvxjVnejHGfY0f35n1JCal/zyEhtd7H +W+3+WbtLFGk6xgm8MFi1st8mg6dfIGui1mgdekala4DexmGEmIZ6SdhHsNxFp22Z1g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793971481; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=hKpKEIGZkNEV40wUkRon/TI5cez2CWRwc9V8Ae7ZysY=; b=eZLRmp6yEV6jF3kxviR1X1fkrPC6z0kc3J+/NYxapgP9wgaD98nT1PTNOMBXTyQtTXjE CmFkwMbsTaSrfBqKM5agabr6UT0kX0j1lvE+P7TDidX1HYdK9EFc46ZwbMlaLLb6d93NM rmW0ho+avK6WVTvTx6CZWkU+WF8JDisp8sYNm5+vkLVqTejm1iiDgloYPoOkzUNolpa18 d/txsZhaGsgTslFRH/YHuNG21sr0LoNCKnfC6KI/CveHxQyXGUU9GF1r5gl7dzgRoJMTN /HXsrk7id50NCDQweVGh3M2jJYPsZfk7sid5NRhbJhBj2SqzJOlcgFscBI24CfxnuBA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="i54Y/ugU"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D79AC606A329 for ; Fri, 6 Nov 2026 13:24:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=i54Y/ugU Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2F8D1F0089F; Fri, 6 Nov 2026 13:24:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793971480; bh=hKpKEIGZkNEV40wUkRon/TI5cez2CWRwc9V8Ae7ZysY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=i54Y/ugU9Kx9lnFJShrS84DiEJZsmbyorjsQ0rLYRkj9f2QOjdieMhhjfFCEiIJQA yzz57f/eoKCTgR6qWxt2QeLiCoKJCBrXuWFd99Blu9rzCMZrOOeABwW5cKQM9lOD7V ZXohrmxdVd64OOkNZeUfmxWy8MxXEL5c88hKVE5G60uU5HoGzAOF1tEw5HNYKpY3YQ NgkDk6bEoKlSbIZwvli0I1kuHGLP7pnZ6KEHXI4lbz2++4hxlYZkdbaRPfEDMFCKvP vv5SAImryw70bYaZu564NpTDxnmk/e7/ceTXc/beVLU9pkmU/n+4PYWirvROq5gS/x M6HmbxWmk1dBQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Peter Ujfalusi , Takashi Iwai , Sasha Levin Subject: [PATCH 6.18.y] ALSA: x86: hdmi: fix chmap array missing terminator entry Date: Fri, 6 Nov 2026 08:24:38 -0500 Message-ID: <20261106132300.64154-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110457-overhung-helper-62a6@gregkh> References: <2026110457-overhung-helper-62a6@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Peter Ujfalusi [ Upstream commit f5e1a9a3fddab8421416b68bb132ae9626d07156 ] had_build_channel_allocation_map() allocates a single struct snd_pcm_chmap_elem via kzalloc() and stores it as intelhaddata->chmap->chmap. struct snd_pcm_chmap.chmap is expected to be a zero-terminated array (see snd_pcm_std_chmaps[]), but had_register_chmap_ctls() never overrides the TLV callback installed by snd_pcm_add_chmap_ctls(), so the generic pcm_chmap_ctl_tlv() from ALSA core is left in place. pcm_chmap_ctl_tlv() is reachable by any local user via SNDRV_CTL_IOCTL_TLV_READ on the "Playback Channel Map" control and walks the array with "for (map = info->chmap; map->channels; map++)". Since the driver's single element is never terminated, this walks past the allocation. The same pointer is also freed on hot-unplug and rebuilt on hot-plug under intelhaddata->mutex, while the TLV callback runs under card->controls_rwsem without that mutex, so the walk can also race a concurrent free of the array. Fix this by allocating a second, zeroed element so the array is properly terminated, and by dropping the inherited TLV callback entirely at registration time, since the driver never implements one of its own. Fixes: 5dab11d89777 ("ALSA: x86: hdmi: Add audio support for BYT and CHT") Cc: stable@vger.kernel.org Signed-off-by: Peter Ujfalusi Link: https://patch.msgid.link/20261008085411.13742-1-peter.ujfalusi@linux.intel.com Signed-off-by: Takashi Iwai [ sashal: Adapted the allocation hunk to replace kzalloc(sizeof(*chmap), GFP_KERNEL) instead of kzalloc_obj(*chmap). ] Signed-off-by: Sasha Levin --- sound/x86/intel_hdmi_audio.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c index 8e2a007311d36..21ee9c9154804 100644 --- a/sound/x86/intel_hdmi_audio.c +++ b/sound/x86/intel_hdmi_audio.c @@ -475,7 +475,8 @@ static void had_build_channel_allocation_map(struct snd_intelhad *intelhaddata) kfree(intelhaddata->chmap->chmap); intelhaddata->chmap->chmap = NULL; - chmap = kzalloc(sizeof(*chmap), GFP_KERNEL); + /* info->chmap must be zero-terminated; allocate a spare terminator entry */ + chmap = kzalloc_objs(*chmap, 2); if (!chmap) return; @@ -575,6 +576,12 @@ static int had_register_chmap_ctls(struct snd_intelhad *intelhaddata, intelhaddata->chmap->kctl->info = had_chmap_ctl_info; intelhaddata->chmap->kctl->get = had_chmap_ctl_get; intelhaddata->chmap->chmap = NULL; + + /* drop the inherited TLV read: it walks chmap without our mutex */ + intelhaddata->chmap->kctl->tlv.c = NULL; + intelhaddata->chmap->kctl->vd[0].access &= + ~(SNDRV_CTL_ELEM_ACCESS_TLV_READ | SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK); + return 0; } -- 2.53.0