diff options
| author | Vivek Goyal <vgoyal@redhat.com> | 2016-07-13 11:13:56 -0400 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2016-08-08 20:06:53 -0400 |
| commit | d8ad8b49618410ddeafd78465b63a6cedd6c9484 (patch) | |
| tree | 7e03ed05fdfae31da74e34856d2f9c718f896c6e /fs/overlayfs | |
| parent | 8b31f456c72e53ee97474a538bcd91bfb1b93fb7 (diff) | |
| download | linux-d8ad8b49618410ddeafd78465b63a6cedd6c9484.tar.bz2 | |
security, overlayfs: provide copy up security hook for unioned files
Provide a security hook to label new file correctly when a file is copied
up from lower layer to upper layer of a overlay/union mount.
This hook can prepare a new set of creds which are suitable for new file
creation during copy up. Caller will use new creds to create file and then
revert back to old creds and release new creds.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: whitespace cleanup to appease checkpatch.pl]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/copy_up.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 54e5d6681786..c297b1f5a05e 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -246,6 +246,8 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, struct dentry *upper = NULL; umode_t mode = stat->mode; int err; + const struct cred *old_creds = NULL; + struct cred *new_creds = NULL; newdentry = ovl_lookup_temp(workdir, dentry); err = PTR_ERR(newdentry); @@ -258,10 +260,23 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, if (IS_ERR(upper)) goto out1; + err = security_inode_copy_up(dentry, &new_creds); + if (err < 0) + goto out2; + + if (new_creds) + old_creds = override_creds(new_creds); + /* Can't properly set mode on creation because of the umask */ stat->mode &= S_IFMT; err = ovl_create_real(wdir, newdentry, stat, link, NULL, true); stat->mode = mode; + + if (new_creds) { + revert_creds(old_creds); + put_cred(new_creds); + } + if (err) goto out2; |