5.4-stable review patch. If anyone has any objections, please let me know.
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From: Vasiliy Kovalev kovalev@altlinux.org
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 miklos@szeredi.hu Link: https://lore.kernel.org/linux-unionfs/CAJfpegvx-oS9XGuwpJx=Xe28_jzWx5eRo1y90... Signed-off-by: Vasiliy Kovalev kovalev@altlinux.org Cc: stable@vger.kernel.org Signed-off-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/overlayfs/util.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -111,6 +111,9 @@ bool ovl_dentry_remote(struct dentry *de
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 |