From 4da697451b10586de95b03c3931061bce10a252e Mon Sep 17 00:00:00 2001 From: Vasiliy Kovalev Date: Tue, 11 Mar 2025 08:51:19 +0900 Subject: [PATCH] ovl: Filter invalid inodes with missing lookup function BugLink: https://bugs.launchpad.net/bugs/2101915 commit c8b359dddb418c60df1a69beea01d1b3322bfe83 upstream. Add a check to the ovl_dentry_weird() function to prevent the processing of directory inodes that lack the lookup function. This is important because such inodes can cause errors in overlayfs when passed to the lowerstack. Reported-by: syzbot+a8c9d476508bd14a90e5@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=a8c9d476508bd14a90e5 Suggested-by: Miklos Szeredi Link: https://lore.kernel.org/linux-unionfs/CAJfpegvx-oS9XGuwpJx=Xe28_jzWx5eRo1y900_ZzWY+=gGzUg@mail.gmail.com/ Signed-off-by: Vasiliy Kovalev Cc: Signed-off-by: Amir Goldstein Signed-off-by: Greg Kroah-Hartman CVE-2024-56570 Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- fs/overlayfs/util.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index a8e17f14d7a2..f4d3daa98f5d 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -197,6 +197,9 @@ void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, bool ovl_dentry_weird(struct dentry *dentry) { + if (!d_can_lookup(dentry) && !d_is_file(dentry) && !d_is_symlink(dentry)) + return true; + return dentry->d_flags & (DCACHE_NEED_AUTOMOUNT | DCACHE_MANAGE_TRANSIT | DCACHE_OP_HASH |