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
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Vasiliy Kovalev <kovalev@xxxxxxxxxxxx>
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@xxxxxxxxxxxx
Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Vasiliy Kovalev <kovalev@xxxxxxxxxxxx>
Reported-by: syzbot+66c146268dc88f4341fd@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=66c146268dc88f4341fd [1]
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Changwei Ge <gechangwei@xxxxxxx>
Cc: Jun Piao <piaojun@xxxxxxxxxx>
Cc: Kurt Hackel <kurt.hackel@xxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Vasiliy Kovalev <kovalev@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxx are
ocfs2-validate-l_tree_depth-to-avoid-out-of-bounds-access.patch
