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 5F6A844C4FF for ; Fri, 11 Sep 2026 19:55:38 +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=1789156547; cv=none; b=YEs2iNu3DHrtr1ayFUvsRUuKrWrwfeADw3AHtsGlEQ9KjMrGWYWRpn6K1cSwRgArAz1fOHsJ9XN/oxqGuCXxw/otd5fmthPO6d5qPnSd143tYEotCWWNLtvXP01X58KeROrdZxITv4PQUjhzYWGqa4IO9xxkRrjFql3vc070nDU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156547; c=relaxed/simple; bh=7gXFL7quQr2EJdsE6WbXzGOKPLlhSMTKAYSI7b39RL4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=qs00kTO2OgkY7YbzfxGr28mj/VzGBGoBMUZ7KoIHVI9pEnVq5mTr4m2YEgSXiuvcS8WsJHNg/b9uQXFeRLvfgU4Xf3oFGr2bNJd9vUacjApmClp09DFXVnjC9otqOSWv/TkGBzk7dludZmNeTYIDtup3+SiC1fOLDGTpTCTHKWk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xJquqsO4; 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="xJquqsO4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC7AC1F0089B; Fri, 11 Sep 2026 19:55:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156535; bh=b3hIVJag3JRt+Rk5IyLXb4uvPe7SrQOP5nyL1Pa3erU=; h=From:To:Cc:Subject:Date:Reply-To; b=xJquqsO4pErc2Hw+y2qeYanZjOr6eqru8fb4HCc2fH2nbHXvJCZeH+/7QMXgxGdNI ToFk+M2sEXeelQr/Z7uQ0TojSR1cM8/dqB76Pzv5RiWEjyjXZxNmCe2+W5FX0cvTei Kl27s694d/93msbBDi4dGmXHkfrcab1H1Q3ouPmQ= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89548: SUNRPC: always drain cache_cleaner before destroying a cache_detail Date: Fri, 11 Sep 2026 21:43:57 +0200 Message-ID: <2026091120-CVE-2026-89548-d39f@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=3013; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=FLqyoD0v0qbEAG/fjowgMAegG1aRINo1JPK9UlfY3bE=; b=kA0DAAIRMUfUDdst+ykByyZiAGqkWWGirTWZ6lF9Dc625QeSxNdyCcEBRaLyiurzVVpbjcsqh 4hdBAARAgAdFiEE9LYMxb94wiFKMT3LMUfUDdst+ykFAmqkWWEACgkQMUfUDdst+ymIAwCgwamF MNdv9iR5ls4ge3ls7NGp0Y0AnjQZYhAMaZMNtf2VeQSjcyxcuZwu 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: SUNRPC: always drain cache_cleaner before destroying a cache_detail sunrpc_destroy_cache_detail() only cancels the global cache_cleaner delayed_work when cache_list is empty. During per-netns teardown cache_list is never empty because init_net's caches remain registered, so the cancel never fires. After unlink, the caller proceeds to cache_destroy_net() which kfrees the cache_detail while cache_clean() may still hold a dangling pointer to it. The result is a use-after-free: cache_dequeue() takes cd->queue_lock on freed memory, and cache_put() dereferences cd->cache_put as a function pointer from freed slab. Drop the list_empty guard so that cancel_delayed_work_sync() always runs, ensuring any in-flight cache_clean() completes before the cache_detail is freed. Re-arm the cleaner afterwards if other caches are still registered. The Linux kernel CVE team has assigned CVE-2026-89548 to this issue. Affected and fixed versions =========================== Issue introduced in 3.4 with commit 820f9442e711a81749e70c40f149fc54c4ce0ca8 and fixed in 6.12.109 with commit 9d44836f60c8c29bcdb1471fd9202387c642a890 Issue introduced in 3.4 with commit 820f9442e711a81749e70c40f149fc54c4ce0ca8 and fixed in 6.18.50 with commit 2e861ce2aaa468351a6a47c4cbb4971ebb740c7b Issue introduced in 3.4 with commit 820f9442e711a81749e70c40f149fc54c4ce0ca8 and fixed in 7.2.4 with commit 3d60fdf951143d6ef4e352e2f8eb852286701726 Issue introduced in 3.4 with commit 820f9442e711a81749e70c40f149fc54c4ce0ca8 and fixed in 7.3-rc1 with commit f42d0fda0c67695db6bc704b04b7c10240805377 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-2026-89548 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: net/sunrpc/cache.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/9d44836f60c8c29bcdb1471fd9202387c642a890 https://git.kernel.org/stable/c/2e861ce2aaa468351a6a47c4cbb4971ebb740c7b https://git.kernel.org/stable/c/3d60fdf951143d6ef4e352e2f8eb852286701726 https://git.kernel.org/stable/c/f42d0fda0c67695db6bc704b04b7c10240805377