From patchwork Wed Sep 7 01:18:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tasos Sahanidis X-Patchwork-Id: 603843 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9B9AEECAAD3 for ; Wed, 7 Sep 2022 05:54:45 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id CE312852; Wed, 7 Sep 2022 07:53:53 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz CE312852 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1662530083; bh=lVZdGItHyUy3HBM+gA9ehpOh4ieVKRxUtDHsoJaeBj8=; h=Date:To:From:Subject:Cc:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From; b=ild7laDVqnHYdQScs0Bfeo0ZOPQCRSsdXR5DgibJ40xED8yQvYFOCqT74Bqr33bIG WyxTBqI/7BesdTAehu15YkSxNKI2Do73AiAxiXNZdaAEgkDeuDbdsPR2iuqqNCtUqs UaUjKIyvbORuF/6WjwWrhEnGTsEBu0rThuTdaync= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 1D4FAF80528; Wed, 7 Sep 2022 07:53:04 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 64400F800E9; Wed, 7 Sep 2022 03:18:11 +0200 (CEST) Received: from devnull.tasossah.com (devnull.tasossah.com [IPv6:2001:41d0:1:e60e::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 18D92F800E9 for ; Wed, 7 Sep 2022 03:18:04 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 18D92F800E9 Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key) header.d=devnull.tasossah.com header.i=@devnull.tasossah.com header.b="qmFw51LA" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=devnull.tasossah.com; s=vps; h=Content-Transfer-Encoding:Content-Type: Subject:From:Cc:To:MIME-Version:Date:Message-ID:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=q71WqvWLWUjrI5AqinecaUm3s2cTcuSNcpFo9Nx2+Yw=; b=qmFw51LAEwU4aImcBHMDhnqmEY pXJJrRPLqzij7UntBfcQL0OMYsZ7p2YjzGCFwV1lQs2vPGXyslK0IzHcpe3I0fm3j6jw3Q4oby3Qs E4nJ3IZ6zKU/l3RTddv60wjQrLCA0qvTeF2sZOhUwfKYXw54ohXgK3Dq6QeDCZdMelyk=; Received: from [2a02:587:6a02:2200::298] by devnull.tasossah.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1oVjhZ-000P0y-7A; Wed, 07 Sep 2022 04:18:01 +0300 Message-ID: <3707dcab-320a-62ff-63c0-73fc201ef756@tasossah.com> Date: Wed, 7 Sep 2022 04:18:00 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Content-Language: en-US To: alsa-devel@alsa-project.org From: Tasos Sahanidis Subject: [PATCH] ALSA: emu10k1: Fix out of bounds access in snd_emu10k1_pcm_channel_alloc() X-Mailman-Approved-At: Wed, 07 Sep 2022 07:53:00 +0200 Cc: tasos@tasossah.com, tiwai@suse.com X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" The voice allocator sometimes begins allocating from near the end of the array and then wraps around, however snd_emu10k1_pcm_channel_alloc() accesses the newly allocated voices as if it never wrapped around. This results in out of bounds access if the first voice has a high enough index so that first_voice + requested_voice_count > NUM_G (64). The more voices are requested, the more likely it is for this to occur. This was initially discovered using PipeWire, however it can be reproduced by calling aplay multiple times with 16 channels: aplay -r 48000 -D plughw:CARD=Live,DEV=3 -c 16 /dev/zero UBSAN: array-index-out-of-bounds in sound/pci/emu10k1/emupcm.c:127:40 index 65 is out of range for type 'snd_emu10k1_voice [64]' CPU: 1 PID: 31977 Comm: aplay Tainted: G W IOE 6.0.0-rc2-emu10k1+ #7 Hardware name: ASUSTEK COMPUTER INC P5W DH Deluxe/P5W DH Deluxe, BIOS 3002 07/22/2010 Call Trace: dump_stack_lvl+0x49/0x63 dump_stack+0x10/0x16 ubsan_epilogue+0x9/0x3f __ubsan_handle_out_of_bounds.cold+0x44/0x49 snd_emu10k1_playback_hw_params+0x3bc/0x420 [snd_emu10k1] snd_pcm_hw_params+0x29f/0x600 [snd_pcm] snd_pcm_common_ioctl+0x188/0x1410 [snd_pcm] ? exit_to_user_mode_prepare+0x35/0x170 ? do_syscall_64+0x69/0x90 ? syscall_exit_to_user_mode+0x26/0x50 ? do_syscall_64+0x69/0x90 ? exit_to_user_mode_prepare+0x35/0x170 snd_pcm_ioctl+0x27/0x40 [snd_pcm] __x64_sys_ioctl+0x95/0xd0 do_syscall_64+0x5c/0x90 ? do_syscall_64+0x69/0x90 ? do_syscall_64+0x69/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Signed-off-by: Tasos Sahanidis --- sound/pci/emu10k1/emupcm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/pci/emu10k1/emupcm.c b/sound/pci/emu10k1/emupcm.c index b2701a4452d8..48af77ae8020 100644 --- a/sound/pci/emu10k1/emupcm.c +++ b/sound/pci/emu10k1/emupcm.c @@ -124,7 +124,7 @@ static int snd_emu10k1_pcm_channel_alloc(struct snd_emu10k1_pcm * epcm, int voic epcm->voices[0]->epcm = epcm; if (voices > 1) { for (i = 1; i < voices; i++) { - epcm->voices[i] = &epcm->emu->voices[epcm->voices[0]->number + i]; + epcm->voices[i] = &epcm->emu->voices[(epcm->voices[0]->number + i) % NUM_G]; epcm->voices[i]->epcm = epcm; } }