diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2017-05-29 15:15:27 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-13 19:48:12 +0200 |
| commit | b2a40eaef694b35ae39f1924b3bee95595676e25 (patch) | |
| tree | 7e7ebc68a77ec27ed99c1ccc20af9e910b6c92cd | |
| parent | 3291bb532df5181352acfb492fc18b7110172670 (diff) | |
ovl: filter trusted xattr for non-admin
[ Upstream commit a082c6f680da298cf075886ff032f32ccb7c5e1a ]
Filesystems filter out extended attributes in the "trusted." domain for
unprivlieged callers.
Overlay calls underlying filesystem's method with elevated privs, so need
to do the filtering in overlayfs too.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/overlayfs/inode.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 7fb53d055537..16f6db88c8e5 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -227,6 +227,16 @@ int ovl_xattr_get(struct dentry *dentry, const char *name, return res; } +static bool ovl_can_list(const char *s) +{ + /* List all non-trusted xatts */ + if (strncmp(s, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) != 0) + return true; + + /* Never list trusted.overlay, list other trusted for superuser only */ + return !ovl_is_private_xattr(s) && capable(CAP_SYS_ADMIN); +} + ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) { struct dentry *realdentry = ovl_dentry_real(dentry); @@ -250,7 +260,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) return -EIO; len -= slen; - if (ovl_is_private_xattr(s)) { + if (!ovl_can_list(s)) { res -= slen; memmove(s, s + slen, len); } else { |