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 9E0C0424654; Fri, 4 Sep 2026 06:15:36 +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=1788502537; cv=none; b=HV84VEkoSG+aOc7ECM/lbpOBaVR6YwhW3SqTC/g8YmMCvjqiJs/npNRKUyCJHvSUKegL8g4tPGOpPu9fPtym8xF0S0GxT4oktx2m84gzI1H4nkXDE0pQm5R5gsvbte2+7akhJJmRDVDAEOYEl+jo9vS/7Xcj9OIufkpln9i7Ad8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788502537; c=relaxed/simple; bh=0EALMO7Zf92L7yxNYCS2fWyS7wl4WbOQ1sW8WXDzdF4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TGXof1u4riLvgcckntk8GMA0QewEiEfWrnOPdAXgEeJZv+/o2jntDbgoTUc6BDJ6lTlxr/zSwWaMtmA8T4bJc88qydKnNP9j4x6Q7bQIrQiSV1l2R9QQufr4IRwxGNVw3/m68ysQMj13ETyDeSCk54pKJDHi0mQ8p07MeJLK4i0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Vs0xtzhf; 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="Vs0xtzhf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CCF41F00A3D; Fri, 4 Sep 2026 06:15:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788502536; bh=SQ/z2NOmKBd1WUA33yHHm4kBq9G85QvirNThN5kp7ME=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Vs0xtzhf1u+hoZ6hhEKfHt+ivrOBn3fthuILlKsw0+ubWmGkIxuQrR10RwtKZOxcc ntg3RnEPvrtS9xCb3CmzXnlacKOCSAv963yjMnF567OVfrWPyAAYXVd5rmSgzOS77E KM4rfHPR/Bf1ejbVBXUa5L7QqCubQkLl6BDzwWYQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Joseph Qi , Changwei Ge , Heming Zhao , Joel Becker , Jun Piao , Junxiao Bi , Mark Fasheh , Andrew Morton Subject: [PATCH 6.12 243/403] ocfs2: bound namelen in dlm_migrate_request_handler Date: Fri, 4 Sep 2026 07:00:46 +0200 Message-ID: <20260904045740.397248521@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045734.806166532@linuxfoundation.org> References: <20260904045734.806166532@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas commit ea5b5609305a8437bc955a0834a530c12246d78f upstream. Patch series "ocfs2/dlm: bound peer-controlled lengths in the o2dlm". The o2dlm receive handlers trust u8 length and count fields from the wire without bounding them, so a node in a DLM domain can corrupt or panic any other node with a malformed message. Three defects: - dlm_migrate_request_handler() passes migrate->namelen unchecked to dlm_init_mle(), which memcpy()s it into the 32-byte mname[] of an o2dlm_mle slab object: a heap out-of-bounds write of up to ~215 attacker-controlled bytes. - dlm_mig_lockres_handler() passes mres->lockname_len unchecked to dlm_init_lockres(), which memcpy()s it into the 32-byte o2dlm_lockname slab object: a heap out-of-bounds write of up to ~223 bytes. - the same handler trusts mres->num_locks without checking that the message is large enough to hold that many entries, so dlm_process_recovery_data() walks mres->ml[] past the kmalloc(data_len) copy and trips a BUG_ON (an out-of-bounds read ending in a panic). The other o2dlm receive handlers already reject an oversized name; the migration and recovery handlers have omitted it since the DLM was added (see the Fixes tags). Patch 1 bounds namelen; patch 2 validates lockname_len, num_locks, and the payload size. Conforming recovery and migration traffic is unaffected. o2net authenticates peers only by the DLM domain key, so any node that has joined the domain -- including a compromised or malicious member -- can send these messages. There is no local trigger; the attacker must already be a member of the cluster. Each sink was confirmed under KASAN with an out-of-tree module mirroring it exactly -- a kmem_cache/kmalloc of the real destination size, then the same unclamped memcpy/loop: slab-out-of-bounds Write for the two writes, Read for the recovery walk, and a panic. A userspace AddressSanitizer build faults identically under -m32 and -m64. Scrubbed logs are available on request. I reported this privately to security@kernel.org and the ocfs2 maintainers on 2026-06-20; with no response after the standard embargo period I am posting the fix publicly. I have no embargo requirement. This patch (of 2): A node receiving a DLM_MIGRATE_REQUEST message trusts the peer-supplied name length (migrate->namelen) without bounding it. dlm_init_mle() then copies that many bytes into the fixed DLM_LOCKID_NAME_MAX-byte mname[] array of an o2dlm_mle slab object, so a malformed message from a cluster peer overflows the slab object by up to ~215 bytes: a heap out-of-bounds write of attacker-controlled data, reachable by any node in the domain. Reject an oversized name, the way dlm_master_request_handler() and the other o2dlm receive handlers already do; the migration handler omits the check entirely. Conforming messages are unaffected. Link: https://lore.kernel.org/20260629-b4-disp-94fb6521-v1-0-6953bcc0421f@proton.me Link: https://lore.kernel.org/20260629-b4-disp-94fb6521-v1-1-6953bcc0421f@proton.me Fixes: 6714d8e86bf4 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem") Signed-off-by: Bryam Vargas Reviewed-by: Joseph Qi Cc: Changwei Ge Cc: Heming Zhao Cc: Joel Becker Cc: Jun Piao Cc: Junxiao Bi Cc: Mark Fasheh Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/dlm/dlmmaster.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -3112,6 +3112,12 @@ int dlm_migrate_request_handler(struct o name = migrate->name; namelen = migrate->namelen; + if (namelen > DLM_LOCKID_NAME_MAX) { + mlog(ML_ERROR, "%s: invalid name length %u in migrate request\n", + dlm->name, namelen); + ret = -EINVAL; + goto leave; + } hash = dlm_lockid_hash(name, namelen); /* preallocate.. if this fails, abort */