From: Vasiliy Kovalev Date: Fri, 14 Feb 2025 08:49:08 +0000 (+0300) Subject: ocfs2: validate l_tree_depth to avoid out-of-bounds access X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=28331a6f84237decedc3789c1feae965bd693bcb;p=users%2Fwilly%2Fpagecache.git ocfs2: validate l_tree_depth to avoid out-of-bounds access 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 Reported-by: syzbot+66c146268dc88f4341fd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=66c146268dc88f4341fd [1] Reviewed-by: Joseph Qi Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Kurt Hackel Cc: Mark Fasheh Cc: Vasiliy Kovalev Signed-off-by: Andrew Morton --- diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index 4414743b638e8..b8ac85b548c7e 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -1803,6 +1803,14 @@ static int __ocfs2_find_path(struct ocfs2_caching_info *ci, 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",