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=1793987633; b=imS1gjIGqL8tB7XLteERScUQ6grSLfel28KxKr0nAdUbQQJGo/V8odLFmrb07ceegXWS AFhOJWLMJ1U9oNPRUMpmBrMm09eyKwvblWnX7YBG+GKCUZxHpw8SCQafV5M32q/E5GcDE ajyhcQs7X7CAAjfODBMYMZ2YuKDqUqr3GYruxgb9Zzb5bR9Z1RP6U5CBnqsTz8wySjx/N MEKKMpA9VUmeJHTip6GPMizPg7B7m+ivHn4b7HWWuoMNGPoD3oLSo9kkbPHMpIlzDmOhN V/ZRBeYGolSs4m5BswwCiABqreRxIdL6fEWK/5dMlYYcmCod2FsK/Fiw7scyIL+H4lg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793987633; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=nIRRaxr6c78JfmX57gzDduG8ByWqww/HI4yYn5Vy6ME=; b=uAEv8stWjLuKAijNchvJquvGqbUGR2tTlcjfr70GELfv84ICYqT3FQUyShiVZ8Z8xTCP 69vRle+3Lnyk02GtEbvK24RQzLIt0Ndc+d4c540YtVtUao4yC2iUaWwdUtii0prv3falM KXOIJRRlX11HV5jnw722p6BA+nflXu+qOB2oZ/nNHFdsyDmFf67J1Q8EhAvd6EausfmRH W8andOYUv1v4GKUZeW5yXa0VrgupHnvoRghwOwZdFbuorptlsNlt2H7mdSO3S55kNyJvs cdul/qPw8yH89dx9XnGYs51zCrhDrWOwrFbrD7OZGNzshl7Tlfej0luKw7ma9lnB+Sw== 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=PqxkMtWr; 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 DB405606A32D for ; Fri, 6 Nov 2026 17:53:52 +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=PqxkMtWr Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C6F41F0089F; Fri, 6 Nov 2026 17:53:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793987632; bh=nIRRaxr6c78JfmX57gzDduG8ByWqww/HI4yYn5Vy6ME=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PqxkMtWr+qzMQlOG+198zM5kvwm71fXneQOiG0w2WL5r9LHmxcOWumsTk7s8HdTb/ YemVCHp5q12zJo3RjX+AAfNcEq53rDYvRwdleqVvFCGQjTXTa7fRQQ+ttrogvxI5ZB rcM0/v7HW2lDVHLi3acTdCQ74/HP/ho7dR3g85PeHUoVmFB3oK9rSLCdTqGlGnJEPs dQOY5V1/XB+q8CpGOUxFdObJ/hFVj7jXYYk+FJ+vTeZAJSEga4W72UpIgSUikSFYbr L9zt3C90UJ6nWbuWewK6fUVB9sqIY5hIZvq2V9zs7cfjL1zvLUOosf9j4acLqIgyhK iD6vW4TGufHgg== From: Sasha Levin To: stable@vger.kernel.org Cc: Peter Ujfalusi , Takashi Iwai , Sasha Levin Subject: [PATCH 5.10.y] ALSA: x86: hdmi: fix chmap array missing terminator entry Date: Fri, 6 Nov 2026 12:53:50 -0500 Message-ID: <20261106175313.451723-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110407-contour-racing-fa1a@gregkh> References: <2026110407-contour-racing-fa1a@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() with kcalloc() using an explicit element size and 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 dbaa43ffbbd2d..81ce6d8f5058c 100644 --- a/sound/x86/intel_hdmi_audio.c +++ b/sound/x86/intel_hdmi_audio.c @@ -476,7 +476,8 @@ 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; @@ -579,6 +580,12 @@ 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