[merged mm-nonmm-stable] ocfs2-validate-lengths-in-dlm_mig_lockres_handler.patch removed from -mm tree

[merged mm-nonmm-stable] ocfs2-validate-lengths-in-dlm_mig_lockres_handler.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: ocfs2: validate lengths in dlm_mig_lockres_handler
has been removed from the -mm tree.  Its filename was
     ocfs2-validate-lengths-in-dlm_mig_lockres_handler.patch

This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Bryam Vargas <hexlabsecurity@proton.me>
Subject: ocfs2: validate lengths in dlm_mig_lockres_handler
Date: Mon, 29 Jun 2026 00:01:44 -0500

A node receiving a DLM_MIG_LOCKRES message trusts several fields of the
peer-supplied dlm_migratable_lockres without validation.  num_locks and
lockname_len are bounded only on the sending side, and the message is
never checked to actually carry num_locks migratable_lock entries.  As a
result dlm_process_recovery_data() walks mres->ml[0..num_locks) past the
kmalloc(data_len) copy of the message (an out-of-bounds read that ends in
a BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the
fixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write). 
Both are reachable by any node in the domain.

Validate these fields right after dlm_grab(), before anything uses them --
including the not-joined error path, which already prints mres->lockname
with the unbounded lockname_len as a %.*s precision.  Reject the message
unless lockname_len <= DLM_LOCKID_NAME_MAX, num_locks <=
DLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the
payload is large enough to hold the claimed locks.  Conforming recovery
and migration messages are unaffected.

Link: https://lore.kernel.org/20260629-b4-disp-94fb6521-v1-2-6953bcc0421f@proton.me
Fixes: 6714d8e86bf4 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ocfs2/dlm/dlmrecovery.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/fs/ocfs2/dlm/dlmrecovery.c~ocfs2-validate-lengths-in-dlm_mig_lockres_handler
+++ a/fs/ocfs2/dlm/dlmrecovery.c
@@ -1357,6 +1357,15 @@ int dlm_mig_lockres_handler(struct o2net
 	if (!dlm_grab(dlm))
 		return -EINVAL;
 
+	if (mres->lockname_len > DLM_LOCKID_NAME_MAX ||
+	    mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS ||
+	    be16_to_cpu(msg->data_len) < struct_size(mres, ml, mres->num_locks)) {
+		mlog(ML_ERROR, "%s: invalid lockres migration message from %u\n",
+		     dlm->name, mres->master);
+		dlm_put(dlm);
+		return -EINVAL;
+	}
+
 	if (!dlm_joined(dlm)) {
 		mlog(ML_ERROR, "Domain %s not joined! "
 			  "lockres %.*s, master %u\n",
_

Patches currently in -mm which might be from hexlabsecurity@proton.me are