To match names beginning with the letters "f" or "b" one can use
the regular expression "[fb].*" or "(f|b).*", but not "[f|b].*",
which would match strings beginning with "f", "|", or "b".
Signed-off-by: Christian von Roques <roques@z12.ch>
Long Wang [Sat, 8 Jul 2017 02:29:57 +0000 (10:29 +0800)]
af_unix: remove unlink operation
It is not necessary to unlink the abstract socket pathname when
we have finished using the socket. The abstract name is automatically
removed when the socket is closed.
This patch allows users to start containers in AppArmor namespaces.
Users can define their own profiles for their containers, but
lxc-start must be allowed to change to a namespace.
A container configuration file can wrap a container in an AppArmor
profile using lxc.aa_profile.
A process in an AppArmor namespace is restricted to view
or manage only the profiles belonging to this namespace, as if no
other profiles existed. A namespace can be created as follow:
sudo mkdir /sys/kernel/security/apparmor/policy/namespaces/$NAMESPACE
AppArmor can stack profiles so that the contained process is bound
by the intersection of all profiles of the stack. This is achieved
using the '//&' operator as follow:
In this case, even the guest process appears unconfined in the
namespace, it is still confined by $PROFILE.
A guest allowed to access "/sys/kernel/security/apparmor/** rwklix,"
will be able to manage its own profile set, while still being
enclosed in the topmost profile $PROFILE:
Different guests can be assigned the same namespace or different
namespaces. In the first case, they will share their profiles.
In the second case, they will have distinct sets of profiles.
use cppcheck tools `cppcheck --enable=warning .` on lxc source directory.
This patch fix the following warnning
```
[src/lxc/cgroups/cgfs.c:794]: (warning) %ld in format string (no. 3) requires 'long' but the argument type is 'unsigned long'.
[src/lxc/confile.c:4441]: (warning) %d in format string (no. 2) requires 'int' but the argument type is 'unsigned int'.
[src/lxc/confile.c:4502]: (warning) %d in format string (no. 2) requires 'int' but the argument type is 'unsigned int'.
[src/lxc/confile_legacy.c:921]: (warning) %d in format string (no. 2) requires 'int' but the argument type is 'unsigned int'.
[src/lxc/confile_legacy.c:938]: (warning) %d in format string (no. 2) requires 'int' but the argument type is 'unsigned int'.
[src/lxc/lxclock.c:63]: (warning) %zd in format string (no. 1) requires 'ssize_t' but the argument type is 'size_t {aka unsigned long}'.
[src/lxc/tools/lxc_info.c:118]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_info.c:118]: (warning) %u in format string (no. 2) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_info.c:123]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_info.c:127]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_info.c:130]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_top.c:212]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_top.c:212]: (warning) %u in format string (no. 2) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_top.c:217]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_top.c:221]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/lxc/tools/lxc_top.c:224]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
```
In case the lxc command socket is hashed and the socket was created for a
different path than the one we're currently querying
lxc_cmd_get_{lxcpath,name}() can return NULL. The command socket path is hashed
when len(lxcpath) > sizeof(sun_path) - 2.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
These functions define pointer to their key shifted by a
number and guard access to it later via another variable.
Let's make this more explicit (and additionally have the
pointer be NULL in the case where it is not supposed to be
used).
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Thomas Jarosch [Thu, 2 Feb 2017 11:48:35 +0000 (12:48 +0100)]
lxc_setup_tios(): Ignore SIGTTOU and SIGTTIN signals
Prevent an endless loop while executing lxc-attach in the background:
The kernel might fire SIGTTOU while an ioctl() in tcsetattr()
is executed. When the ioctl() is resumed and retries,
the signal handler interrupts it again.
We can't configure the TTY to stop sending
the signals in the first place since that
is a modification/write to the TTY already.
Still we clear the TOSTOP flag to prevent further signals.
Command to reproduce the hang:
----------------------------
cat > lxc_hang.sh << EOF
/usr/bin/timeout 5s /usr/bin/lxc-attach -n SOMECONTAINER -- /bin/true
EOF
sh lxc_hang.sh # hangs
----------------------------
Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Previous versions of lxc-attach simply attached to the specified namespaces of
a container and ran a shell or the specified command without first allocating a
pseudo terminal. This made them vulnerable to input faking via a TIOCSTI ioctl
call after switching between userspace execution contexts with different
privilege levels. Newer versions of lxc-attach will try to allocate a pseudo
terminal master/slave pair on the host and attach any standard file descriptors
which refer to a terminal to the slave side of the pseudo terminal before
executing a shell or command. Note, that if none of the standard file
descriptors refer to a terminal lxc-attach will not try to allocate a pseudo
terminal. Instead it will simply attach to the containers namespaces and run a
shell or the specified command.
(This is a backport of a series of patches fixing CVE-2016-10124.)
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
- Make escape sequence to exit tty optional since we want to reuse
lxc_console_cb_tty_stdin() in lxc_attach.c.
- Export the following functions since they can be reused in other modules:
- lxc_console_cb_tty_stdin()
- lxc_console_cb_tty_master()
- lxc_setup_tios(int fd, struct termios *oldtios);
- lxc_console_winsz(int srcfd, int dstfd);
- lxc_console_cb_sigwinch_fd(int fd, uint32_t events, void *cbdata, struct lxc_epoll_descr *descr);
- lxc_tty_state *lxc_console_sigwinch_init(int srcfd, int dstfd);
- lxc_console_sigwinch_fini(struct lxc_tty_state *ts);
- rewrite lxc_console_set_stdfds()
- Make lxc_console_set_stdfds useable by other callers that do not have
access to lxc_handler.
- Use ssh settings for ptys.
- Remove all asserts from console.{c,h}.
- Adapt start.c to changes.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Serge Hallyn [Mon, 6 Mar 2017 19:36:19 +0000 (13:36 -0600)]
seccomp: set SCMP_FLTATR_ATL_TSKIP if available
Newer libseccomp has a flag called SCMP_FLTATR_ATL_TSKIP which
allows syscall '-1' (nop) to be executed. Without that flag,
debuggers cannot skip system calls inside containers. For reference,
see the seccomp(2) manpage, which says:
The tracer can skip the system call by changing the system call number to -1.
Adam Borowski [Sun, 12 Feb 2017 06:26:54 +0000 (07:26 +0100)]
seccomp: allow x32 guests on amd64 hosts.
Without this patch, x32 guests (and no others) worked "natively" with x32
host lxc, but not on regular amd64 hosts. That was especially problematic
as a number of ioctls such as those needed by netfilter don't work in such
scenarios, thus you want to run amd64 on the host.
With the patch, you can use all three ABIs: i386 x32 amd64 on amd64 hosts.
Despite x32 being little used, there's no reason to deny it by default:
the admin needs to compile their own kernel with CONFIG_X86_X32=y or (on
Debian) boot with syscall.x32=y. If they've done so, it is a reasonable
assumption they want x32 guests.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
CVE-2017-5985: Ensure target netns is caller-owned
Before this commit, lxc-user-nic could potentially have been tricked into
operating on a network namespace over which the caller did not hold privilege.
This commit ensures that the caller is privileged over the network namespace by
temporarily dropping privilege.
Launchpad: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1654676 Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Colin Watson [Thu, 26 Jan 2017 14:32:08 +0000 (14:32 +0000)]
Make lxc-start-ephemeral Python 3.2-compatible
On Ubuntu 12.04 LTS with Python 3.2, `lxc-start-ephemeral` breaks as
follows:
Traceback (most recent call last):
File "/usr/bin/lxc-start-ephemeral", line 371, in attach_as_user
File "/usr/lib/python3.2/subprocess.py", line 515, in check_output
File "/usr/lib/python3.2/subprocess.py", line 732, in __init__
LookupError: unknown encoding: ANSI_X3.4-1968
This is because `universal_newlines=True` causes `subprocess` to use
`io.TextIOWrapper`, and in versions of Python earlier than 3.3 that
fetched the preferred encoding using `locale.getpreferredencoding()`
rather than `locale.getpreferredencoding(False)`, thereby changing the
locale and causing codecs to be reloaded. However, `attach_as_user`
runs inside the container and thus can't rely on having access to the
same Python standard library on disk.
The workaround is to decode by hand instead, avoiding the temporary
change of locale.
projects / thirdparty / lxc.git / log
