From 470c15636125d1591bc901f6aa2d8e4a60ed2190 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Mon, 13 Jul 2020 17:19:43 +0300 Subject: [PATCH] ovl: force read-only sb on failure to create index dir With index feature enabled, on failure to create index dir, overlay is being mounted read-only. However, we do not forbid user to remount overlay read-write. Fix that by setting ofs->workdir to NULL, which prevents remount read-write. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- fs/overlayfs/super.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 94ca095..f41ef1d 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1352,12 +1352,13 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, goto out; } + /* index dir will act also as workdir */ + iput(ofs->workdir_trap); + ofs->workdir_trap = NULL; + dput(ofs->workdir); + ofs->workdir = NULL; ofs->indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true); if (ofs->indexdir) { - /* index dir will act also as workdir */ - iput(ofs->workdir_trap); - ofs->workdir_trap = NULL; - dput(ofs->workdir); ofs->workdir = dget(ofs->indexdir); err = ovl_setup_trap(sb, ofs->indexdir, &ofs->indexdir_trap, @@ -1869,7 +1870,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) if (!ovl_upper_mnt(ofs)) sb->s_flags |= SB_RDONLY; - if (!(ovl_force_readonly(ofs)) && ofs->config.index) { + if (!ovl_force_readonly(ofs) && ofs->config.index) { err = ovl_get_indexdir(sb, ofs, oe, &upperpath); if (err) goto out_free_oe; -- 2.7.4