From nobody Tue Aug 25 15:59:20 2026 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4hTssj2lBLz6pbGP for ; Tue, 25 Aug 2026 15:59:21 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "YR2" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4hTssj0Vsfz419l for ; Tue, 25 Aug 2026 15:59:21 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1787673561; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=v8JLaVG843QQKrqPPXzks5xBApp9uS37EjUOucQS204=; b=GsE9Qzrect9h4WJAWpedUoTTlaF5onKd37Hx2PfcMTv4O7GHB2yxLkvZL9WAKDeyZjgDdC d70xPYXMACo9kMlIkR2bZYDK9KmUGXADlogPR/4qf99ZzEfuFBGrt733GUaj1Gb7KTRzJS AiOQaRxnmD0ChrGM39T9sr5+sGfkORytUwdRr9X+hwSAJC+hidsMye2EUz8wRihJ/abuYg /2p/H2cXFP6hLMtAHmDJIsZOOpIU94uj3/O382HIp21USB1Xzpa4EnrBNyqJcwRy6/I6KT 9UHjfUQtGSKAlfVqtbeRMfbnRKWSuhO8qZXFSTo8OUKP3ID0rjsLj4WOnykFVA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1787673561; a=rsa-sha256; cv=none; b=cDuiP1rIddgWr4r+ntCA0XvQSOL9+Rz5VgsVXhnqGtoUxK1f+L9qNmvkgpu7hYlg2C4aog 3ZGcplF4ejjITTmTJHZqWMxF/BURn+phtjiCFfl3jW1FAZpv+879OGqcp0LwqYWdx9/cNa SzNDTjHuum2oyWusvH2gw523XgZKJEnpQ8xW4NBtPWkXWo7XEFJiyufyXgoyvNmiYQu4Je ioNPCBaqGqozAOakUe4UkuWV02SJBedAAf7tmOchs6cJJcy71ECXUzy3oa5Heg1ly34WNw zMW4nYBwb2iZE2I4wo/YRvWvIxgC9ZktIUIPdmnu7EQbrM3IQ9jxTXQcRRY4Vw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1787673561; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=v8JLaVG843QQKrqPPXzks5xBApp9uS37EjUOucQS204=; b=ifNnsqPGvk5mUXnjlem3+yVbOVMP+cgzKR464KiXIsNqLd7E9m8h/OVRocFQjdOndI03Kd 1TQN6E1w9NtZDIjNRmWiVePwhMBorRWbEv3ZU2RLvu5Yu9Vp+5EONAtFhWhsUp3pTCe9Cn hiqNGLAQc03cc4kjnM/+GYJT+nv5GxYTeBJcBQX+SgsvC3R9ahXGo7+5yaVYJmuMPDZ0lK Jo8MBD4Y0y1czNwawCbqT0evO2RUigYeuUonGfzQERcogaTs0d/5OMyjBqkxYun4sOBfTe v1HH9xc577mCCXdCUodulCJUStuj63MazBG7UOtvFQX+f8OLzdufgplqvwIXKA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4hTssh5zznzxt5 for ; Tue, 25 Aug 2026 15:59:20 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 3184c by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 25 Aug 2026 15:59:20 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: 62c4afcb4604 - main - dsp: Fix a potential use-after-free in dsp_oss_syncstart() List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 62c4afcb460457bae055d756b24d5b5e5535903c Auto-Submitted: auto-generated Date: Tue, 25 Aug 2026 15:59:20 +0000 Message-Id: <6a8dbbd8.3184c.776ad8cf@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=62c4afcb460457bae055d756b24d5b5e5535903c commit 62c4afcb460457bae055d756b24d5b5e5535903c Author: Mark Johnston AuthorDate: 2026-08-24 15:20:32 +0000 Commit: Mark Johnston CommitDate: 2026-08-25 15:46:24 +0000 dsp: Fix a potential use-after-free in dsp_oss_syncstart() This function has a loop where it attempts to lock all channels in a group. If doing so would block, it releases all locks, sleeps for a bit, and tries again. However, once the syncgroup lock is dropped, nothing prevents the syncgroup structure from being freed. Fix the inner loop: after waking up, break out of it unconditionally and start everything again. I think the old code was also buggy and not well-exercised: after waking up we'd continue to try and continue locking channels. Then we'd try again from the beginning and fail to lock the channels we had already locked. Approved by: so Security: FreeBSD-SA-26:58.sound Security: CVE-2026-58091 Reported by: Hazley Samsudin of GovTech CSG Reviewed by: christos Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D58912 --- sys/dev/sound/pcm/channel.h | 9 +++++---- sys/dev/sound/pcm/dsp.c | 17 ++++++----------- 2 files changed, 11 insertions(+), 15 deletions(-) diff --git a/sys/dev/sound/pcm/channel.h b/sys/dev/sound/pcm/channel.h index aac6ab368625..2f71f0708c8e 100644 --- a/sys/dev/sound/pcm/channel.h +++ b/sys/dev/sound/pcm/channel.h @@ -57,10 +57,11 @@ struct pcmchan_syncmember; extern struct mtx snd_pcm_syncgroups_mtx; extern SLIST_HEAD(pcm_synclist, pcmchan_syncgroup) snd_pcm_syncgroups; -#define PCM_SG_LOCK() mtx_lock(&snd_pcm_syncgroups_mtx) -#define PCM_SG_TRYLOCK() mtx_trylock(&snd_pcm_syncgroups_mtx) -#define PCM_SG_UNLOCK() mtx_unlock(&snd_pcm_syncgroups_mtx) -#define PCM_SG_LOCKASSERT(arg) mtx_assert(&snd_pcm_syncgroups_mtx, arg) +#define PCM_SG_LOCKPTR() (&snd_pcm_syncgroups_mtx) +#define PCM_SG_LOCK() mtx_lock(PCM_SG_LOCKPTR()) +#define PCM_SG_TRYLOCK() mtx_trylock(PCM_SG_LOCKPTR()) +#define PCM_SG_UNLOCK() mtx_unlock(PCM_SG_LOCKPTR()) +#define PCM_SG_LOCKASSERT(arg) mtx_assert(PCM_SG_LOCKPTR(), arg) /** * @brief Specifies an audio device sync group diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c index 18d679c81433..c92c55b02cff 100644 --- a/sys/dev/sound/pcm/dsp.c +++ b/sys/dev/sound/pcm/dsp.c @@ -2684,14 +2684,11 @@ dsp_oss_syncstart(int sg_id) struct pcmchan_syncmember *sm, *sm_tmp; struct pcmchan_syncgroup *sg; struct pcm_channel *c; - int ret, needlocks; + int ret; - /* Get the synclists lock */ PCM_SG_LOCK(); - do { ret = 0; - needlocks = 0; /* Search for syncgroup by ID */ SLIST_FOREACH(sg, &snd_pcm_syncgroups, link) { @@ -2728,16 +2725,14 @@ dsp_oss_syncstart(int sg_id) } /** @todo Is PRIBIO correct/ */ - ret = msleep(sm, &snd_pcm_syncgroups_mtx, + ret = msleep(sm, PCM_SG_LOCKPTR(), PRIBIO | PCATCH, "pcmsg", timo); - if (ret == EINTR || ret == ERESTART) - break; - - needlocks = 1; - ret = 0; /* Assumes ret == EAGAIN... */ + if (ret == EAGAIN) + ret = 0; + break; } } - } while (needlocks && ret == 0); + } while (ret == 0 && sm != NULL); /* Proceed only if no errors encountered. */ if (ret == 0) {