+ ocfs2-validate-l_tree_depth-to-avoid-out-of-bounds-access.patch added to mm-nonmm-unstable branch

+ ocfs2-validate-l_tree_depth-to-avoid-out-of-bounds-access.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: ocfs2: validate l_tree_depth to avoid out-of-bounds access
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     ocfs2-validate-l_tree_depth-to-avoid-out-of-bounds-access.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-validate-l_tree_depth-to-avoid-out-of-bounds-access.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Vasiliy Kovalev <kovalev@altlinux.org>
Subject: ocfs2: validate l_tree_depth to avoid out-of-bounds access
Date: Fri, 14 Feb 2025 11:49:08 +0300

The l_tree_depth field is 16-bit (__le16), but the actual maximum depth is
limited to OCFS2_MAX_PATH_DEPTH.

Add a check to prevent out-of-bounds access if l_tree_depth has an invalid
value, which may occur when reading from a corrupted mounted disk [1].

Link: https://lkml.kernel.org/r/20250214084908.736528-1-kovalev@altlinux.org
Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org>
Reported-by: syzbot+66c146268dc88f4341fd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=66c146268dc88f4341fd [1]
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.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: Kurt Hackel <kurt.hackel@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Vasiliy Kovalev <kovalev@altlinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ocfs2/alloc.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/fs/ocfs2/alloc.c~ocfs2-validate-l_tree_depth-to-avoid-out-of-bounds-access
+++ a/fs/ocfs2/alloc.c
@@ -1803,6 +1803,14 @@ static int __ocfs2_find_path(struct ocfs
 
 	el = root_el;
 	while (el->l_tree_depth) {
+		if (unlikely(le16_to_cpu(el->l_tree_depth) >= OCFS2_MAX_PATH_DEPTH)) {
+			ocfs2_error(ocfs2_metadata_cache_get_super(ci),
+				    "Owner %llu has invalid tree depth %u in extent list\n",
+				    (unsigned long long)ocfs2_metadata_cache_owner(ci),
+				    le16_to_cpu(el->l_tree_depth));
+			ret = -EROFS;
+			goto out;
+		}
 		if (le16_to_cpu(el->l_next_free_rec) == 0) {
 			ocfs2_error(ocfs2_metadata_cache_get_super(ci),
 				    "Owner %llu has empty extent list at depth %u\n",
_

Patches currently in -mm which might be from kovalev@altlinux.org are

ocfs2-validate-l_tree_depth-to-avoid-out-of-bounds-access.patch