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 96C7358FD03 for ; Fri, 11 Sep 2026 20:00:30 +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=1789156838; cv=none; b=ISTpIRG/5PxgVG+rnHzFo99AhXlMtXfBjizXYI2gqBSPyNnlHPusLsBZSgDsfQIzRo+d3kgdJ19N30OvdjAzR4Jp6eSpXnab/eUd6IhOqEovB6pTv/kShIYLSa3MwuRN8L7ZPgGadINQ2PcCd6t72gCv2EzBm5uRFItGcY8lWWA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156838; c=relaxed/simple; bh=A3e0qgKEpSiR/VB8SBUqtxSj2JdSGnKvFKNO24/kKr0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=ZwspD8o8ABiR/DY+U5t5CuhkIV6edSjNyuqy4H5OMvkbMQJakBOUc7uxru3taRkIaWxMhMHbLnY+fr3CraYVedaWE1sG7i4ScLlooZ65fMfbjybItu4ATahIcpjFvUEqjPAP0peleEZVmq9dnUy/QyZEmYkLglZ7KymLlftoGJ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OcN4J0cw; 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="OcN4J0cw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F11401F00898; Fri, 11 Sep 2026 20:00:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156829; bh=NSKcvaOHef3h8D7TbwpvIQEEBDSQIni7QBTTlHuJMls=; h=From:To:Cc:Subject:Date:Reply-To; b=OcN4J0cwvNLy+rGC+sCVlh2GKnO/zQ1SQX7nR9M5xM06rveKRrLtF42bbsqjoz85o ZM9+KdA2HUZZa7mRsuPM1d/SVz4ihXhxJKfaocOHAtoISgXFnz3V+PDrH1M2OWTnNl Gql9eAW5EmognIn9r5N1H757+9SoUyVFruQkpbK8= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89646: ceph: fix leaked inode reference on writeback abort at umount Date: Fri, 11 Sep 2026 21:45:35 +0200 Message-ID: <2026091143-CVE-2026-89646-e6a3@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=3619; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=SnV9DgaFgyxxFPAIk4MnKodoMYO+EOeSEjNCVnxo1ls=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIss1xGI+aL6qES789NOmrNZKWuVwW7i3t/SOSYtfb OC4/uNwRwwLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzE/TzD/KQQsa9W9VZT5jC/ Pt8is+3Fs2dtHAzT66O2rw9buiA3V2rerFm/ohf/C7gGAA== 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: ceph: fix leaked inode reference on writeback abort at umount ceph_dirty_folio() takes a wrbuffer claim on each newly dirtied folio: it bumps i_wrbuffer_ref (taking an ihold() on the 0->1 transition) and attaches the snap_context to folio->private. That claim is released only by ceph_put_wrbuffer_cap_refs(), which for a submitted write runs from writepages_finish(). In ceph_submit_write(), if ceph_inc_osd_stopping_blocker() fails -- which happens during umount -- the request is aborted before submission: the already-collected folios are only redirtied and unlocked, so writepages_finish() never runs and the claim is leaked. redirty_page_for_writepage() -> folio_redirty_for_writepage() -> filemap_dirty_folio() sets PG_dirty directly and does not go through ->dirty_folio, so ceph_dirty_folio() is not re-entered to rebalance it. Because every subsequent writeback also fails the osd_stopping_blocker, i_wrbuffer_ref never returns to 0, the ihold() is never dropped, and the inode cannot be evicted: VFS: Busy inodes after unmount of ceph kernel BUG at fs/super.c:650! Release the orphaned claim in the abort path before redirtying, via ceph_undo_wrbuffer_claim(): detach the snap_context, drop the wrbuffer reference (letting i_wrbuffer_ref reach 0 and iput() the inode), and drop the snap_context reference -- i.e. do what writepages_finish() would have done for these never-submitted folios. Only the locked_pages entries are undone; folios still in the fbatch were never dirty-cleared by this call (folio_clear_dirty_for_io() is the ownership-transfer point, and a successful move NULLs the fbatch slot), so they hold no claim this call owns. The Linux kernel CVE team has assigned CVE-2026-89646 to this issue. Affected and fixed versions =========================== Issue introduced in 6.15 with commit fd7449d937e7fb3144770592927cf452bf66dbd3 and fixed in 6.18.50 with commit ec32015a955c5d326c5e26610edfdcccd52f2314 Issue introduced in 6.15 with commit fd7449d937e7fb3144770592927cf452bf66dbd3 and fixed in 7.2.4 with commit ac7a5a5385762df458d10cccc086a4e079be7409 Issue introduced in 6.15 with commit fd7449d937e7fb3144770592927cf452bf66dbd3 and fixed in 7.3-rc1 with commit c25aee9c630fb86f98d79eccb75765067079b972 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-2026-89646 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/ceph/addr.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/ec32015a955c5d326c5e26610edfdcccd52f2314 https://git.kernel.org/stable/c/ac7a5a5385762df458d10cccc086a4e079be7409 https://git.kernel.org/stable/c/c25aee9c630fb86f98d79eccb75765067079b972