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| author | Miklos Szeredi <mszeredi@redhat.com> | 2021-11-04 10:55:34 +0100 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2021-11-04 10:55:34 +0100 |
| commit | 1f5573cfe7a7056e80a92c7a037a3e69f3a13d1c (patch) | |
| tree | 529a98c4445e34dc1f806c760b2668f0b46ec27c /fs/overlayfs/super.c | |
| parent | ovl: fix use after free in struct ovl_aio_req (diff) | |
| download | linux-1f5573cfe7a7056e80a92c7a037a3e69f3a13d1c.tar.xz linux-1f5573cfe7a7056e80a92c7a037a3e69f3a13d1c.zip | |
ovl: fix warning in ovl_create_real()
Syzbot triggered the following warning in ovl_workdir_create() ->
ovl_create_real():
if (!err && WARN_ON(!newdentry->d_inode)) {
The reason is that the cgroup2 filesystem returns from mkdir without
instantiating the new dentry.
Weird filesystems such as this will be rejected by overlayfs at a later
stage during setup, but to prevent such a warning, call ovl_mkdir_real()
directly from ovl_workdir_create() and reject this case early.
Reported-and-tested-by: syzbot+75eab84fd0af9e8bf66b@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/super.c')
| -rw-r--r-- | fs/overlayfs/super.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 178daa5e82c9..265181c110ae 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -787,10 +787,14 @@ retry: goto retry; } - work = ovl_create_real(dir, work, OVL_CATTR(attr.ia_mode)); - err = PTR_ERR(work); - if (IS_ERR(work)) - goto out_err; + err = ovl_mkdir_real(dir, &work, attr.ia_mode); + if (err) + goto out_dput; + + /* Weird filesystem returning with hashed negative (kernfs)? */ + err = -EINVAL; + if (d_really_is_negative(work)) + goto out_dput; /* * Try to remove POSIX ACL xattrs from workdir. We are good if: |