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 B139158F076 for ; Fri, 11 Sep 2026 20:01:04 +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=1789156874; cv=none; b=oyQVtznMbeKt475x16D1/7+yarLs+GD6vtd47IoI874v2mtXBlh7RAgNplZZpQjG+w3RdRSJci6PaSMf+b3khvEPyv1863yx032xbyT3KOaf583pJ3ZfpHhh5niskbk6UHo3kbVH2gE31gg1yByTPaIx4TXJkqxj6hN0yfTmOho= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156874; c=relaxed/simple; bh=9IbokEpE9ME9RoszoTYV3/zHtjgzegoPdcEfRn2LP00=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=PqqUuBZ2rufoW+b8gVVWsGtsJw8dO2TK9h3qh+b8leWM1RG2gnxTaggsf0a3BJe8UH5C0LEHb7IVWrnDpZE9Bt2NXBjEr07m3dsqS8IYM7wsf48LD522xy0UqY8EyGQ3Tq+EagRD62VBtS5h4ElVlGv4npLy/gIbOdqauAA6zDQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yNgt+FeC; 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="yNgt+FeC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 626391F000FF; Fri, 11 Sep 2026 20:01:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156862; bh=7V2VbGGcwjh2tosYCeTcynucTrW5Vhtpy+jqqJOR7Z8=; h=From:To:Cc:Subject:Date:Reply-To; b=yNgt+FeCgVCVVGFxs3ewU7Lh1ozz9yHhy4FU+OLSfa41V28HtiKN7ah7Ktlmt677c RN08WOyPOdgYa1QiGFdIGdhQn86ZWdcsacPfyV9h+e9EBtccgntRfsImJ0yNjMari8 9fDsdGzmdU9O/qf9rCvpDY4D4YV4fMxehzRcA7EI= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89656: libceph: reject buckets with mismatched CRUSH ids Date: Fri, 11 Sep 2026 21:45:45 +0200 Message-ID: <2026091145-CVE-2026-89656-e2e3@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=3090; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=k8UzMscPXYjdz0CypCgN3Ml/Pga9SEKikoNDjs6KTiE=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIitNLPfe4Fj+ZJlT7Q15lehW5++tFcI/vz9IjV+69 ozFg235HbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjARfQ6GuYLvHuTujr4jKGOS P7nmUsbm6UaPcxjm++efm1mXdLB0eaSLbc10caONOvf8AA== 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: libceph: reject buckets with mismatched CRUSH ids crush_decode() stores bucket data by array slot, and the mapper later derives the per-bucket workspace index from the decoded bucket id. A malformed map can therefore make one bucket reuse another bucket's workspace by encoding an id different from -1 - slot. For uniform buckets, the second replica selection expands the source bucket's permutation into that aliased workspace buffer. If the source bucket is larger than the aliased bucket, the write runs past the smaller permutation array and can escape the kvmalloc'd CRUSH workspace. KASAN reports a slab OOB write of 4 bytes in bucket_perm_choose(). Reject buckets whose encoded id does not match their array slot. Valid CRUSH maps already use the canonical negative id corresponding to the bucket slot, so this restores the invariant expected by work->work[-1 - in->id] without changing valid map behavior. The Linux kernel CVE team has assigned CVE-2026-89656 to this issue. Affected and fixed versions =========================== Issue introduced in 4.11 with commit 66a0e2d579dbec5c676cfe446234ffebb267c564 and fixed in 6.12.109 with commit 3516a4131c4e45d62ee4e42e82c36930e8c1fbbd Issue introduced in 4.11 with commit 66a0e2d579dbec5c676cfe446234ffebb267c564 and fixed in 6.18.50 with commit 00562ccd4e88d092b9b851df50fad20442bfeb24 Issue introduced in 4.11 with commit 66a0e2d579dbec5c676cfe446234ffebb267c564 and fixed in 7.2.4 with commit 79900d978158b2d80eef952fc41b9e4dc58d7b83 Issue introduced in 4.11 with commit 66a0e2d579dbec5c676cfe446234ffebb267c564 and fixed in 7.3-rc1 with commit 3cde4a8302301679937474a5f7a851394cc1bd11 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-2026-89656 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/ceph/osdmap.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/3516a4131c4e45d62ee4e42e82c36930e8c1fbbd https://git.kernel.org/stable/c/00562ccd4e88d092b9b851df50fad20442bfeb24 https://git.kernel.org/stable/c/79900d978158b2d80eef952fc41b9e4dc58d7b83 https://git.kernel.org/stable/c/3cde4a8302301679937474a5f7a851394cc1bd11