From: Amir Goldstein Date: Tue, 3 Oct 2023 06:21:27 +0000 (+0300) Subject: ovl: fix NULL pointer defer when encoding non-decodable lower fid X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c7242a45cb8cad5b6cd840fd4661315b45b1e841;p=linux.git ovl: fix NULL pointer defer when encoding non-decodable lower fid A wrong return value from ovl_check_encode_origin() would cause ovl_dentry_to_fid() to try to encode fid from NULL upper dentry. Reported-by: syzbot+2208f82282740c1c8915@syzkaller.appspotmail.com Fixes: 16aac5ad1fa9 ("ovl: support encoding non-decodable file handles") Signed-off-by: Amir Goldstein --- diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c index c8c8588bd98ca..26b782c53910b 100644 --- a/fs/overlayfs/export.c +++ b/fs/overlayfs/export.c @@ -188,7 +188,7 @@ static int ovl_check_encode_origin(struct dentry *dentry) /* Lower file handle for non-upper non-decodable */ if (!ovl_dentry_upper(dentry) && !decodable) - return 0; + return 1; /* Upper file handle for pure upper */ if (!ovl_dentry_lower(dentry))