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 218A45908A9 for ; Fri, 11 Sep 2026 20:02:14 +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=1789156944; cv=none; b=dOZjcJLHkuXeTE/HvusRdu540e8lZRqhudJoS8ZW71o11vLlzbxfwMi5oMS/aY7Un4QJIkLBk1HQJkmPoF6Dg0432TvO32yA0qbDUfXNuFWGVY/FuLFNHMOsaWj7bZKRkQp/2B0pQOBwz9eZB1JBW3zX3OC2BHvbZmXSj+Ywmvg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156944; c=relaxed/simple; bh=2HLdoTVSDS15nnsGhfmwTbnFV6edEDqWDPMmXiI1x3E=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=pLXZUJPtOFH0rElTYfuyKemDaKUGyfg21BdimdWgF5c/vtjQmD/ZLeNqs7vmSlh+yQTjG4ufFgtRI1ifh2GzErL3wktnolNtYzBOJtd1fqKkQhGA3J0Z4jINPjyen0Yg9qpzqGfR4i0GnUcETCtmf9Si/3Jru6vOXYyj1jCkV78= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Thc6Q0hR; 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="Thc6Q0hR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 555A51F0089C; Fri, 11 Sep 2026 20:02:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156930; bh=tBUu66k+bb5N0XYMu9b8vBQOr3xzcTKF/wOv5cjJ4K8=; h=From:To:Cc:Subject:Date:Reply-To; b=Thc6Q0hRvpDDGf+PKM4D7cNOj7V3aPIUK9X2A6BLk5Qi98iFdfHcgv2oVaA+PdTgv mv+nU4J+6Yc6Yer5by917XoB2YPyrJj1SF+JvcxTLknatzcfKWW3SAeZUUjvgAiH7u UcDSHaDZvXswZYlp/Hnzb9coDoNA9oN+mhgAC624= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89681: nfsd: fix layout fence worker double-reference race Date: Fri, 11 Sep 2026 21:46:10 +0200 Message-ID: <2026091151-CVE-2026-89681-2a18@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=2490; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=TxZ8M5d9fvCEIkEvo8KWflkGAq51PH/LY+Q6MzSOp1I=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIusz3M9aLlh5In5mzmLrFU5LDm2MOHfxk52Y+/1py /wn3XnP0xHLwiDIxCArpsjyZRvP0f0VhxS9DG1Pw8xhZQIZwsDFKQATiStgWHD2e799UBznPuNb l3V/Ghs/NpnH9Zhhwf6S51EHAsVSP7cnRe3QPTlRenr4LQA= 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: nfsd: fix layout fence worker double-reference race The workqueue core clears WORK_STRUCT_PENDING before the callback is invoked, so delayed_work_pending() in lm_breaker_timedout() can return false while the fence worker is already running. This lets the breaker take a duplicate sc_count reference and schedule a new worker that coalesces with the in-progress one. The extra reference is never put, leaking the layout stateid. Replace the racy delayed_work_pending() check with an ls_fence_inflight boolean set atomically with refcount_inc_not_zero() under ls_lock, and cleared under ls_lock before the final nfs4_put_stid() on the dispose path; the retry path intentionally retains it. Remove the self-rearm mod_delayed_work() at the top of the worker. The Linux kernel CVE team has assigned CVE-2026-89681 to this issue. Affected and fixed versions =========================== Issue introduced in 7.1 with commit f52792f484ba2316853736856dde19b7e7458861 and fixed in 7.2.4 with commit a278d361e0e8f242211891193d56483a7a9f47a8 Issue introduced in 7.1 with commit f52792f484ba2316853736856dde19b7e7458861 and fixed in 7.3-rc1 with commit 8580571227451384399b3fa53fcde19848c48e5a 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-2026-89681 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: fs/nfsd/nfs4layouts.c fs/nfsd/state.h 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/a278d361e0e8f242211891193d56483a7a9f47a8 https://git.kernel.org/stable/c/8580571227451384399b3fa53fcde19848c48e5a