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=1793974488; b=MIbuY5MoC0e/2DH5vB+1Eg9dEC2RFPE0S1CBpRa0YRyKQKM4ohgxpniTHHZL16sxL2b3 liBHi0AoSiQibstvlsGjFTSOl2cLfVdTCHqeEE61oFn85O3toT39EDtwRUeOy8/1Dh0Kn nxQAJ5a1LxzRjabyYdZFX8JxNas898Gn0xDxvlpasM4KJPiKP2ADzTaVb8iSgak1N+6Tj 9dM0bm9Eey5G6TzI7RcT+zJ/Dz5C2rQ5NAIL0eUwu3sjdQzwAsGASc3tR+oDU5KWaXYAO wkxXwaNbUOzhjvRq8S0FvolJ7VfzWQita2qJtYcQE5QCX5w+URkPcYtGntHmY2MNKTg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793974488; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=hg/qv4cSR4GK1fnfLKAg4VlnHpxaN1r/opczeazkgJ8=; b=J/CwLlkZINVHAAUG91fsIuQdnFRnI7H59Fa2qvk0bmn1nP9Ljx/7GibDEG+z2cIx3Jyc yQdBC3ju8ybvk9mdVyJ0UfnmVkHUvh6CkYG1D78oBrzHlLFvn0+MjkW6lwyTwmmbgr5dr WvkKBslgOcPX6ZyAU6TCKcRSmvW684Q6XsO/fLTl/D2EKV1QoONXH8khbosY/FFYJko6v bZhnkUv4/zaQotVGY9QICLj2gz1mlF0FfLypbIzJ440r2LPF0NzglRGgVePKtIJLGbovv WeV5AkuZuC1pmrQ/5qsxwGWmPxtK1lSK2wVo/l4j+VtWWq+PtPfI/lgBVwGevgUb0Mg== 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="NqU/cWBO"; 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 6E81A606A329 for ; Fri, 6 Nov 2026 14:14:48 +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=NqU/cWBO Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7FC7C1F0089F; Fri, 6 Nov 2026 14:14:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793974488; bh=hg/qv4cSR4GK1fnfLKAg4VlnHpxaN1r/opczeazkgJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NqU/cWBOzdPvpXKPTPr9FdrQ3uwmZbDRBuybL2mvrRgDegoupAUKgUKPKOA8Zs2yD m20VQLOEPj4jBbSRCDQFBB9U508x0WbTzcTPxck2Tes6sSdA7KghicuHNwHGtVK+hj AFdOI3YeTwR3QtDKvaz93nDDlrFJF2mr/AqwB796iYYsV/xyX8ujGJTpMB+cvuFTNh 7HnLUBgWOQ+wOZB+rdq/QXHz+oKN4jGFXpAwdxJ6KeMk/OZbgdJA8djDruwHzNYinm nf9MCJ9vq/vfEqWGx5GuTWgcwGn2WbEoJHReFd1W9bb4XS4M8z0VolHiWcFjGlRmNE fboODcPXJVRow== From: Sasha Levin To: stable@vger.kernel.org Cc: Peter Ujfalusi , Takashi Iwai , Sasha Levin Subject: [PATCH 6.6.y] ALSA: x86: hdmi: fix chmap array missing terminator entry Date: Fri, 6 Nov 2026 09:14:46 -0500 Message-ID: <20261106141254.287349-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110401-reverence-patriarch-006f@gregkh> References: <2026110401-reverence-patriarch-006f@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: Replaced unavailable kzalloc_objs() with kcalloc(2, sizeof(*chmap), GFP_KERNEL). ] 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 7b9292cf839f2..d23dfdd50440a 100644 --- a/sound/x86/intel_hdmi_audio.c +++ b/sound/x86/intel_hdmi_audio.c @@ -478,7 +478,8 @@ 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 = kcalloc(2, sizeof(*chmap), GFP_KERNEL); if (!chmap) return; @@ -581,6 +582,12 @@ 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