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=1794063519; b=OBftxoI4PVqK2vr2NLqHNXTh/SyPEtNkKTMRgF3+8TVHaEYYXJAp2Caff7NgB37Q8+Az TUHYIjumA1g1rLI5sjfNdIMvoMIWYmoUPUuwJ6b4W9po2su6MrWrUvvOJuFI96CkRAQWk 1FQRHKDGYtn4QdOPH/McFKg6qEM63v96PuhQsqf90smGA9RSwdUIaFcs3ThfwAutu+o8u Z2sy4RAIFitjP2D2CLs1wvh0edV9AZhZXVnuuyDtcP4OFhaj2qU8HPfC68FKQiOfwcbL1 8Dh9FohG26SwfG9AOleyLIEY77p+B84AvIUIyiwiE4vDplPE4AqA4GtVao3ww+7KSuA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063519; 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=S98DjiBxvLFGt5FrsO5hxUeOmvA3opMIwSawWX4d0BM=; b=3rwLQZh4tGX54qDsOdUqb9l2eVRCvvzJOvYNYPr4m9vidTaZLPSwyZUHOvZIVDXYU1rA /CylipiY0oTox17BHet9jWEu7A1n2/jFMd4wcDCfBu7neBkEzjjwCpXlRu1+v0a0+j2w6 xH/NzSi5PBtMGslIqezCEAbjW2XYCvq9dDQRI1E5WeHCnot7bSsCaJRnpC2tY9APJcdhK NIGt5+wiEOqVGLJtv3TzSe9Aj2QTMMm/KDIfgEd7Avuck97xWHAzFXT9Qj7rMAYJ7BWWU DCNt+XKQPyFcVyQXLNPstRdzWF4SspxjOrKmSxtpahZBqGkhNxAq8LWvSb3f6kAxX2g== 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=1LX+Zg2z; 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 54CA1606B8AF; Sat, 7 Nov 2026 14:58:39 +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=1LX+Zg2z Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1ED01F008A1; Sat, 7 Nov 2026 14:58:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063519; bh=S98DjiBxvLFGt5FrsO5hxUeOmvA3opMIwSawWX4d0BM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1LX+Zg2zM9/+UsOGA0UMSmX6Lds33QX2Y9OawxkhniwSoTO8Aqt23Y4qED2PGU8rA QrCYp7029KujQTo0zXUvsh5+Lji4EzV95yE9zIjLyk2pbYIXnXY6/yd1pNyuS0oV6e asANRNBTu/4DZFmt5TvjNOhapeB2fWijQCboZ1rU= 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 6.18 660/869] ALSA: compress: reject buffer geometry change on gapless next_track Date: Sat, 7 Nov 2026 08:55:42 -0500 Message-ID: <20261107134915.489587705@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Ujfalusi [ Upstream commit 82da1acad6fd60b6072dd5f3383e6a55efdd2ac7 ] snd_compr_set_params() is invoked from the gapless next_track re-entry path, which calls snd_compr_allocate_buffer() again and lets buffer_size change while total_bytes_available and total_bytes_transferred still hold values computed for the previous buffer. snd_compr_calc_avail() then derives an avail/count value from those stale counters against the new buffer_size, and snd_compr_write_data() copy_from_user()s that many bytes into the new, potentially smaller buffer, overflowing it with user-controlled length and content. The buffer is set up once, with the initial SET_PARAMS, and neither the core nor the DSP expects it to change for a gapless track transition. Do not call snd_compr_allocate_buffer() on the next_track path and reject a request that changes the buffer geometry, so that the codec parameters that the driver receives match the buffer in use. Fixes: 9727b490e543 ("ALSA: compress: add support for gapless playback") Cc: stable@vger.kernel.org Signed-off-by: Peter Ujfalusi Link: https://patch.msgid.link/20261019144533.30665-3-peter.ujfalusi@linux.intel.com Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/compress_offload.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index c4114186b0d11..b707bdbb97069 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -656,9 +656,19 @@ snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg) if (retval) return retval; - retval = snd_compr_allocate_buffer(stream, params); - if (retval) - return -ENOMEM; + if (stream->next_track) { + /* + * total_bytes_available/transferred still refer to the + * current buffer; its geometry must not change. + */ + if (params->buffer.fragment_size != stream->runtime->fragment_size || + params->buffer.fragments != stream->runtime->fragments) + return -EINVAL; + } else { + retval = snd_compr_allocate_buffer(stream, params); + if (retval) + return retval; + } retval = stream->ops->set_params(stream, params); if (retval) { -- 2.53.0