| Message ID | 20250103032837.815858-1-sunjunchao2870@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/2] ocfs2: Check el->l_next_free_rec in ocfs2_get_clusters_nocache | expand |
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c index f7672472fa82..83d3343b3e3c 100644 --- a/fs/ocfs2/extent_map.c +++ b/fs/ocfs2/extent_map.c @@ -435,6 +435,15 @@ static int ocfs2_get_clusters_nocache(struct inode *inode, } } + if (le16_to_cpu(el->l_next_free_rec) > le16_to_cpu(el->l_count)) { + ret = ocfs2_error(inode->i_sb, "Invalid dinode #%llu: next_free_rec is %u, count is %u\n", + (unsigned long long)di_bh->b_blocknr, + le16_to_cpu(di->id2.i_list.l_next_free_rec), + le16_to_cpu(di->id2.i_list.l_count)); + + goto out; + } + i = ocfs2_search_extent_list(el, v_cluster); if (i == -1) { /*
Hi, Recently syzbot reported a use-after-free issue[1]. The root cause of the problem is that the journal inode recorded in this file system image is corrupted. The value of "di->id2.i_list.l_next_free_rec" is 8193, which is greater than the value of "di->id2.i_list.l_count" (19). To solve this problem, an additional check should be added within ocfs2_get_clusters_nocache(). If the check fails, an error will be returned and the file system will be set to read-only. [1]: https://lore.kernel.org/all/67577778.050a0220.a30f1.01bc.GAE@google.com/T/ Reported-and-tested-by: syzbot+2313dda4dc4885c93578@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2313dda4dc4885c93578 Signed-off-by: Julian Sun <sunjunchao2870@gmail.com> --- fs/ocfs2/extent_map.c | 9 +++++++++ 1 file changed, 9 insertions(+)