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=1793976357; b=P0AgE6BHJkKdIBIhbgtMh77T66Tz76ZoKD4rnd/e5vWWxAcWtSvcnQHfYS2xKcfOVROx 9jeVIOKeBkebo9Vxtd8Y9fvn5JLzTKRBH3mOEm4QSxKj/pbeqspiNIkEHzDqlGXWQJnBM UAQQDOyOZrfANUoQs3G68Lz2xXbg+iqnKOwuAJTps1wkbNTKCtu6vLuEqecAsIYdprJPY fd4IkVfbXWIjTpHf4wEx52iAZjgqxU4+n/fZNkbs/lbPTKg8JDt0EEGwhN8jcKvz60MqC qOGuJUoIMa1w8Hh4S2dF50lRCDdF9c8/cakzF1YUTq8DHHFAzVJOH1PP0EzbvZVEn5Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793976357; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=9TS2JBQB/04hlFmEYypV1L6oXgwgf4IiLVUY9vF3/LU=; b=b1JSTkiOd1wT3NOFtwNHvNFDlB+Kc5Zr33IwQAmLBeSnUzdNI6CcF/C7LZNi7mO6sUQh V9yv9sHVumUkQLd2A5gWkiHzx/Wj5fOJ4jmevh/3ybvnhPvsLe+0U7ctgRqnK2i6wJEhN c88bKIC4Lsb6kms4vjGpTVjnkJmCaPCYrv73A5bdHyObn0drl63OHA9JmINYnTwm/P1GQ P+ZxmrlcDDiOLXlpG5wiYWWbCxfxc3U+iRTRPgdQNkM5hWlmpPU+eD9zoUFB5/QW24oDl 27XKAQS1kQ8+W1D2saWHNW3268oUukvdIpNUtf3UTjuc+VyPJABG1mbhoEgNDcOuftQ== 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=MLjlmLpG; 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 812D6606A326 for ; Fri, 6 Nov 2026 14:45:57 +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=MLjlmLpG Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0D341F0089F; Fri, 6 Nov 2026 14:45:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793976357; bh=9TS2JBQB/04hlFmEYypV1L6oXgwgf4IiLVUY9vF3/LU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MLjlmLpGBReQThpaTNUtlbmfTYTPNvqyQGEtEvL6B2KY3Dr1v59EiqG+VbtsAi8hh u5gTMkeNHh9TLGTHoGpKfgn9Nhx+dh4+LCIkYnhAPXBJqn+T76FHfLcfjS1B9RqsTO wKAb6p+p5SXMEi1nwbt+KJqc5oiNw2sertTgvN/ka7+0lOChQbqSRivM+1QaJ+kaXw dOsYEGBVvthR14w7dhOmpsSAEcJ9eZjSBpD70KlkSuawPl3ck6rrmwmPvgCecGnW8m ENKvr6+3mIXl2qy7iSMymHaN2TRv1jUKgrir4u9MIBabY2X+F1f0M7HDTRirGARoOu loGAXueuyF2BA== From: Sasha Levin To: stable@vger.kernel.org Cc: Peter Ujfalusi , Takashi Iwai , Sasha Levin Subject: [PATCH 6.1.y] ALSA: x86: hdmi: fix chmap array missing terminator entry Date: Fri, 6 Nov 2026 09:45:55 -0500 Message-ID: <20261106144334.360069-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110403-postbox-magenta-0986@gregkh> References: <2026110403-postbox-magenta-0986@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 kzalloc_objs(*chmap, 2) 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