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=1793978406; b=S+8vG5Jca0JkiHjYgjkRqW+JuWbpf+wK+TV5A+aXJK3srlIeZ8SF2eLMCLhn3OcB1z9Z oNXnfgVp51XEmNhTVEn1lldDbFZIXLZArGITCZZfbLGnlonWwCDBmbvyIe+0c9PShC8L6 Fwf1KRi//2LXc4w8fM6FZmhHfFTpsvypm87aTwGU0CTnFPPIHmh21JaZVINGw5fHWnjhD 71P9+AuX699z7vpA4j8pxh/xpCadIi9GN15+kspLaehlqeMFuCE7iim0lB6FkO2G5e/XK wBolNi2rZfGlFacOl6+A0bg7z8dmh3dUn3XSGBYOZPTG384cFqTlVCHKmGHPtWrv8rA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793978406; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=1zPgQ5RnPHec006OGsQVhFYA7XTWxFr9hmIrm+JvQvk=; b=ygkXYcNe4HOyEnEyvg5G43Tn4nJsiueHXBt/1YQgfndwCzDTs7hreAPPrb3IXFexZ/iN qATJhtp2FQ+tr/bmSLaGXWlHTA44FgNpW4sHtLdfLgK5yilhnnUW+4W51wmlNGZXBK6uT ifLZNFJK03nZHNcO2M+tBLve+yeGQ5SB3UOy3v7nDdDiW/kuRKBKl60R90d8W5OPTLnBX 3jA1IrMK7FNGtrolGvATHExS1x73cwAbMd1LG+eroSPG/S4Fbsj3+05oqR85pSHRqTZ1D gJOcA3tG9dkfcm1fXgh9Lki+vpz6WhGT2JRF3InlKbjTffppKo2Ou1/JHv1a4yIbStA== 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=FACWn8ap; 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 D8193606EE81 for ; Fri, 6 Nov 2026 15:20:05 +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=FACWn8ap Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7F181F00901; Fri, 6 Nov 2026 15:20:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793978405; bh=1zPgQ5RnPHec006OGsQVhFYA7XTWxFr9hmIrm+JvQvk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FACWn8ap8hp520FAoFn/TX7YQXw5cXUuaNNj1onI7RSjqMh5LcRak5cdAx9Iq9K9f UgsF2sVMvVV1Mjg+iEjGfNNdwmZB87q8MMpJBWNAQIXB2sSky/1dm13E0NmjxlUVBS B8q5w7XBNt7x8Ofv1f60E3xJlltylMWgNhRViHywYpX/51KIiGmk1vPH/TFI63whb0 edJqFllALmF6jDB6Oi2ozstdG3OFdGYLrByur7q4j5x1E0sJHGVmKmFA1Z/R5i3xvz Z0N/ZyZxLeJIQS+Bw1no8jr/qBZRgcmA3VFKs9YhKxII5CteO/cDonlskvjI51ao5L BR7bAu+gAlE4A== From: Sasha Levin To: stable@vger.kernel.org Cc: Peter Ujfalusi , Takashi Iwai , Sasha Levin Subject: [PATCH 5.15.y] ALSA: x86: hdmi: fix chmap array missing terminator entry Date: Fri, 6 Nov 2026 10:20:03 -0500 Message-ID: <20261106151923.401559-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110405-molar-buffalo-85ed@gregkh> References: <2026110405-molar-buffalo-85ed@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 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 ff80ac3e1cbab..0a6b78cb9c2a8 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