| Message ID | 20250106023432.1320904-1-sunjunchao2870@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v5,1/2] ocfs2: Check el->l_next_free_rec in ocfs2_get_clusters_nocache | expand |
On 2025/1/6 10:34, Julian Sun wrote: > 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> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> > --- > fs/ocfs2/extent_map.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c > index f7672472fa82..930150ed5db1 100644 > --- a/fs/ocfs2/extent_map.c > +++ b/fs/ocfs2/extent_map.c > @@ -435,6 +435,16 @@ static int ocfs2_get_clusters_nocache(struct inode *inode, > } > } > > + if (le16_to_cpu(el->l_next_free_rec) > le16_to_cpu(el->l_count)) { > + ocfs2_error(inode->i_sb, > + "Inode %lu has an invalid extent (next_free_rec %u, count %u)\n", > + inode->i_ino, > + le16_to_cpu(el->l_next_free_rec), > + le16_to_cpu(el->l_count)); > + ret = -EROFS; > + goto out; > + } > + > i = ocfs2_search_extent_list(el, v_cluster); > if (i == -1) { > /*
I really appreciate your comments and suggestions, thank you! Joseph Qi <joseph.qi@linux.alibaba.com> 于2025年1月6日周一 13:30写道： > > > > On 2025/1/6 10:34, Julian Sun wrote: > > 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> > > Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> > > --- > > fs/ocfs2/extent_map.c | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c > > index f7672472fa82..930150ed5db1 100644 > > --- a/fs/ocfs2/extent_map.c > > +++ b/fs/ocfs2/extent_map.c > > @@ -435,6 +435,16 @@ static int ocfs2_get_clusters_nocache(struct inode *inode, > > } > > } > > > > + if (le16_to_cpu(el->l_next_free_rec) > le16_to_cpu(el->l_count)) { > > + ocfs2_error(inode->i_sb, > > + "Inode %lu has an invalid extent (next_free_rec %u, count %u)\n", > > + inode->i_ino, > > + le16_to_cpu(el->l_next_free_rec), > > + le16_to_cpu(el->l_count)); > > + ret = -EROFS; > > + goto out; > > + } > > + > > i = ocfs2_search_extent_list(el, v_cluster); > > if (i == -1) { > > /* >
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c index f7672472fa82..930150ed5db1 100644 --- a/fs/ocfs2/extent_map.c +++ b/fs/ocfs2/extent_map.c @@ -435,6 +435,16 @@ static int ocfs2_get_clusters_nocache(struct inode *inode, } } + if (le16_to_cpu(el->l_next_free_rec) > le16_to_cpu(el->l_count)) { + ocfs2_error(inode->i_sb, + "Inode %lu has an invalid extent (next_free_rec %u, count %u)\n", + inode->i_ino, + le16_to_cpu(el->l_next_free_rec), + le16_to_cpu(el->l_count)); + ret = -EROFS; + goto out; + } + i = ocfs2_search_extent_list(el, v_cluster); if (i == -1) { /*
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 | 10 ++++++++++ 1 file changed, 10 insertions(+)