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=1793972423; b=JWaPlrYivgrFNQYzsydDoQ9V/CtJIgujUap9Vav0XpqUyYPKtw/fVjutDBF7w280V7q+ xVPxHBnKlKzd0sxPenX2OwNqrY7/eD+4GbuUu8N1+aNKZgeBZy9qhEDJ+TVbXMyrWhMZ4 sctnIJbUtAXdyyVIB3F1VOblEn5Xlj/QM/EY50xvNvRDaiv028eR1X4NL1vMjjFSU1jtr I0ZcWmZ0Vtb5p4GjnP09FmI1evzM5OJDXL9/OkPJWCzqVfOmrWQpmmJik7KNxI19lM8o9 t5vS+WtN7yKdfPotau6aLYVBzCW+fNPDflhQ/dsZQkgftztiKWkVtoltBmAeXg79Gfg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793972423; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=792w9wS54QUKFKfvawm4AfGl4A5og/wwJWcek6OYWIk=; b=v8RhzNQH4TCaPMZ6a5kpID1Hds1arD2Zju0U6DnQfVo0ylquXQXHrjAZHWieZENotUPv RUPGw31CyDz68KGGt3HV5BWSYavWBTEcb4aJzId8ABPomba80Rse/YaYY7hwZ3hzMBl+j lalsWLpaIdHMm1sfQP3wyOqkvGXMVjzy236IDb/hXBCQhuUc7SjawqCErlZXEGv5Y0+mV ZmavHLk9GM+9SMbDKJDJth+2H8bMPDkesHTO05S72FE/41CfGjdS0OHjq/AEQC7TFhetD pr756NB1gljRv3UGeQqhuZiZwj+8ckfV7RpfesjI9CbCIjIQvU5lKoW5AIXPI6aXDLQ== 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=Rbh7K6hQ; 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 53DE3606A338 for ; Fri, 6 Nov 2026 13:40:23 +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=Rbh7K6hQ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70C731F0089F; Fri, 6 Nov 2026 13:40:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793972422; bh=792w9wS54QUKFKfvawm4AfGl4A5og/wwJWcek6OYWIk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Rbh7K6hQ7JjSqFcWqUStwpS9AMyUl96Av21wB+L32MVTs4F4uBfwrx3pQLnbgNNw7 fvDo4XoFp5n1ySghLFTnBcMOaUvZ1zmqo61oISF7jGPqiUxYtqe3i+lbDl/LUGpwR9 4BnkGCQBpr2XbmrxAKr3urk9PabnBjAR8Q24F86H1IoM6JOFkqUKdQMqRxahYssB7T RYBS/tFuvqfj1ijY7TJcZVdLXIuB818UEALhz5qtbPnzX3wfvFvWB8zFVlhRYvi397 TB/nRy2MXz8sz846Nk3je7WrsBKepjhuhSbiNGEH1Hxivt8FvAL9TlaDUi6Jw29CnS 0Fx2C9u3eHTFw== From: Sasha Levin To: stable@vger.kernel.org Cc: Peter Ujfalusi , Takashi Iwai , Sasha Levin Subject: [PATCH 6.12.y] ALSA: x86: hdmi: fix chmap array missing terminator entry Date: Fri, 6 Nov 2026 08:40:21 -0500 Message-ID: <20261106133925.249030-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110459-dramatize-kettle-6042@gregkh> References: <2026110459-dramatize-kettle-6042@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: adjusted context for the existing kzalloc(sizeof(*chmap), GFP_KERNEL) call instead of kzalloc_obj() ] 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 571a092b128a2..3c8f1793522ae 100644 --- a/sound/x86/intel_hdmi_audio.c +++ b/sound/x86/intel_hdmi_audio.c @@ -479,7 +479,8 @@ 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; @@ -582,6 +583,12 @@ 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