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| author | Miklos Szeredi <mszeredi@redhat.com> | 2017-05-29 16:15:27 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-13 20:52:16 +0300 |
| commit | 4bcc9b4b3a0a0fcf269558db8bc54cc9586f585f (patch) | |
| tree | 041051a5ccf400d00c0df0c5424943386b35b67e /fs/overlayfs | |
| parent | 0a9936458980e73306980539949a7d700eb700c1 (diff) | |
| download | linux-4bcc9b4b3a0a0fcf269558db8bc54cc9586f585f.tar.xz | |
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>
Diffstat (limited to 'fs/overlayfs')
| -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 6d52041d13cf..df5c2853c4e5 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -258,6 +258,16 @@ ssize_t ovl_getxattr(struct dentry *dentry, const char *name, return vfs_getxattr(realpath.dentry, name, value, size); } +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 path realpath; @@ -282,7 +292,7 @@ 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 { |