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=1794585248; b=WteRjYcwzI5Ef6FeQVWu9OWcOWz6OXE89YT2ANLe5bOXxtci97o0c0wdN5fs+h5S9ji5 N9PJD6rUoc8sIWOdy/62a7JSGyRq1XpqJ3zuWv/C/vekbNKTnmN575sk0x/WDQQYKJSWW 0mr/9eqUFYmsLL/rTspcvP+IAXlWd/dCuTUoFB9+uQs+7rXFqXHQGyE2mwuMTsvjrf00x zQ3I1txzgatM1x0NES/6ZQhbVYR4dB2tEyqUD37ZdO44hfvrQB0sdJpctjUPzCxiA8m/o kOb9Kp5GjNWW0ol1L5Xw9uooCv/B0qAqUXE9H/SeLzQWQMkRbw8Bk3ICmQXVzD9sSKw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794585248; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=lC8fxfBbQ6TOjPUiMiGVTWCg3WYLqwIYRCzbFyAee9Q=; b=ycK5cSOMNb84Yj+vqDJUqHoURKzDEHElgkES/ijM3w3Hq5xFxOuOgxI1pWsdQS0Sk6Mb ow6agvA+mOcFj9d1TU//QeZPxySF6NseIL3CvpcnB/5L9FO1MP3rolm0CLdfxBWx0qitF 49Ko3Vus4ajEbb8FE/WxMSSB/uC0NaT2NHWdRsigzVE6gpRPYWZIokne2V/ugzYQ8E2g6 lB51kw27N38j5J4FwPx6H5j4MX+UTkF5jNCQaNTpID4FObyTdPc5AZsBsTJ6Ygqxxk7I4 XQOfLdG0G8tjzkSf1hZfCnpytGb6kkw7LwpoF762PzLhQrMFBN+HUwuNbXwmu7TcKGQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="f7bs/Pvg"; 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 15C7E606A32D; Fri, 13 Nov 2026 15:54:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=f7bs/Pvg Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5E5A1F000C4; Fri, 13 Nov 2026 15:54:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794585247; bh=lC8fxfBbQ6TOjPUiMiGVTWCg3WYLqwIYRCzbFyAee9Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=f7bs/Pvg/up5VPBy25f61lnCkDbSUoPd4Yerfq3mdveV20ooMN6gvOwTi8G0yaNRH Ev9FLXiHWdWu0+u2wr0Zoy3ADF8Qe+uW1LGJVw+1xnWi7m0ioGAt6Fx1wmOosAbgQz +Ik/C8MS2trmYcFteYgje4QEzohVR7++OwY8Ssng= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Peter Ujfalusi , Takashi Iwai , Sasha Levin Subject: [PATCH 6.18 002/686] ALSA: x86: hdmi: fix chmap array missing terminator entry Date: Fri, 13 Nov 2026 10:42:15 -0500 Message-ID: <20261113153821.013423887@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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