From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 779BB4FDE72 for ; Wed, 16 Sep 2026 10:44:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789555471; cv=none; b=XjnJPx+gd1mKNq/RgLMxsn93tur3awBraS5du/DxXq0nqvOvXPABs8gb4UAe0jAMw4Joxn/BOEWWwczFk14YbTbUyf33lOiJQURbkEVJBhnazuT/zBQKX9zIYjBKnnTMSJpngJ/uZ7gcC/CxZSIeiEs1dDApGgRO8jXo2xoLzrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789555471; c=relaxed/simple; bh=4LKEGSGI/Lgdi2vu0ApQcGq7PzoEInroNiWW7R8+Mu8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Vlk0hzsDf1jw72nBjTw+tyyMRPrkhCAqxjMen1wvkFmzZcVVMSfTfJ/3ivznpT7c0SS86jwjx/wjTZ+iGrhe4RB0dEBx59twml1GbH7P9la4UjJhiepcdxmNKO8r84uPAcW/cHE8uuTYo7oMJ3dFfEjBzx1Krn9PU8g1MtLfIno= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Zz+JcjrK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Zz+JcjrK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3CA51F00893; Wed, 16 Sep 2026 10:44:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789555453; bh=vsDCf+2jRCahULXFyNeGDMHbxkMMRlBRPl5Db1eRLVs=; h=From:To:Cc:Subject:Date:Reply-To; b=Zz+JcjrKr50OfcU8KrO7Dq2HH1xseKV9FtzSQR36fYnqY85/fjmEbElN6qA+Z9mkJ zqO4FKIKnbBaVVcSE9hYBPjHTTCNwZUFIRi5M9qQEgVIwtR6i2A868oOXoIhRd3hvN Vp2OttIzqmLT6PtqxhOOp5zeAg9LFxWmonoVEDGI= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89979: ALSA: pcm: Fix race between non-atomic ops and trigger-start Date: Wed, 16 Sep 2026 11:31:49 +0100 Message-ID: <2026091655-CVE-2026-89979-96dd@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3978; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=vHtwYYNOy/8snBGzaeXidZCmUFuNBk0/zh4ktLf4Zr8=; b=owGbwMvMwCRo6H6F97bub03G02pJDFmr8hfbbecM/dO/oF14vdCueq+1D+oFf7H16LcdT7X0z fF7qX+mI5aFQZCJQVZMkeXLNp6j+ysOKXoZ2p6GmcPKBDKEgYtTACaiL8kwT9/Cw1vmP/M/31N+ j989DDkxh/11JsOCTRyWm7l+iXnN79ReyZqnEvvJyew/AA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix race between non-atomic ops and trigger-start We protect the races of the concurrent state transitions between atomic PCM ops, but the checks between the non-atomic ops (hw_params, hw_free and prepare) and the atomic ops aren't perfect; there is a check of the conflicting PCM state at the beginning of hw_params & co, but the atomic PCM ops can be still issued during the non-atomic PCM operations. An example such scenario is that a thread A re-issues the PREPARE or HW_PARAMS for the already prepared stream, while another thread B triggers the PCM start in the middle of the prepare operation. Although this usually doesn't lead to much serious issues, it can give some inconsistency as reported by syzkaller (such as ODEBUG warning). There are various atomic PCM ops, and basically the only problem is the PCM start as it operates from the PREPARED state. Other trigger commands (stop, etc) are for the running or the other special state, hence they are filtered as pre-condition. This patch is for preventing the PCM trigger-start during the non- atomic operations in order to address the problems above. Fortunately, the hw_params, hw_free and prepare operations call snd_pcm_buffer_access_lock(), and this can be used for checking the concurrent operations at the PCM trigger -- which sets the runtime->buffer_accessing to a negative (if possible), so the PCM trigger just needs to check the runtime->buffer_accessing value; if it's negative, it means the concurrent non-atomic PCM ops is running. The Linux kernel CVE team has assigned CVE-2026-89979 to this issue. Affected and fixed versions =========================== Fixed in 5.10.270 with commit b1d12144557fceed5de6e22e2c2e30a40ed37702 Fixed in 5.15.221 with commit b2edc017f94c08bdd0b046a586e43ac771a2f942 Fixed in 6.1.188 with commit b599e7f16441386754ec083fa62a549bccb02fca Fixed in 6.6.157 with commit ad29779736cfd6f5595f0cab300dd7611418e363 Fixed in 6.12.110 with commit 5abeb4f9f2023f001d693b4e5e1ebbf25e25d0eb Fixed in 6.18.51 with commit 7ad2ea7c10044b08ecf7b04376916faf12e17a99 Fixed in 7.2.5 with commit 50afadf1ea66597116eb14e73c24da7ae99b759f Fixed in 7.3-rc2 with commit acac7b5e07349a9d10d78873afb4b93cd1dc721f Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-89979 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: sound/core/pcm_native.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/b1d12144557fceed5de6e22e2c2e30a40ed37702 https://git.kernel.org/stable/c/b2edc017f94c08bdd0b046a586e43ac771a2f942 https://git.kernel.org/stable/c/b599e7f16441386754ec083fa62a549bccb02fca https://git.kernel.org/stable/c/ad29779736cfd6f5595f0cab300dd7611418e363 https://git.kernel.org/stable/c/5abeb4f9f2023f001d693b4e5e1ebbf25e25d0eb https://git.kernel.org/stable/c/7ad2ea7c10044b08ecf7b04376916faf12e17a99 https://git.kernel.org/stable/c/50afadf1ea66597116eb14e73c24da7ae99b759f https://git.kernel.org/stable/c/acac7b5e07349a9d10d78873afb4b93cd1dc721f