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| author | Pádraig Brady <pbrady@redhat.com> | 2012-07-31 14:05:35 +0100 |
|---|---|---|
| committer | Pádraig Brady <pbrady@redhat.com> | 2012-08-07 20:02:06 +0100 |
| commit | ce4b2e27be45a85b310237615c47eb53f37bb5f3 (patch) | |
| tree | 1d235965a3f5773ab5d7e7588e5c0b4768b05281 /nova/virt | |
| parent | 9d753f18e1c5e4eaa4021f64ac9fe14ef1103b71 (diff) | |
Prohibit file injection writing to host filesystem
This is a refinement of the previous fix in commit 2427d4a9,
which does the file name canonicalization as the root user.
This is required so that guest images could not for example,
protect malicious symlinks in a directory only readable by root.
Fixes bug: 1031311, CVE-2012-3447
Change-Id: I7f7cdeeffadebae7451e1e13f73f1313a7df9c5c
Diffstat (limited to 'nova/virt')
| -rw-r--r-- | nova/virt/disk/api.py | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/nova/virt/disk/api.py b/nova/virt/disk/api.py index 373c4fa52..5d3c9c6c9 100644 --- a/nova/virt/disk/api.py +++ b/nova/virt/disk/api.py @@ -363,7 +363,9 @@ def _join_and_check_path_within_fs(fs, *args): mounted guest fs. Trying to be clever and specifying a path with '..' in it will hit this safeguard. ''' - absolute_path = os.path.realpath(os.path.join(fs, *args)) + absolute_path, _err = utils.execute('readlink', '-nm', + os.path.join(fs, *args), + run_as_root=True) if not absolute_path.startswith(os.path.realpath(fs) + '/'): raise exception.Invalid(_('injected file path not valid')) return absolute_path |