Jeremy Allison [Sun, 27 Feb 2011 17:16:20 +0000 (18:16 +0100)]
Fix denial of service - memory corruption.
CVE-2011-0719
Fix bug #7949 (DoS in Winbind and smbd with many file descriptors open).
All current released versions of Samba are vulnerable to
a denial of service caused by memory corruption. Range
checks on file descriptors being used in the FD_SET macro
were not present allowing stack corruption. This can cause
the Samba code to crash or to loop attempting to select
on a bad file descriptor set.
A connection to a file share, or a local account is needed
to exploit this problem, either authenticated or unauthenticated
(guest connection).
Currently we do not believe this flaw is exploitable
beyond a crash or causing the code to loop, but on the
advice of our security reviewers we are releasing fixes
in case an exploit is discovered at a later date.
Volker Lendecke [Sun, 12 Dec 2010 17:55:06 +0000 (18:55 +0100)]
s3: Add an async smbsock_connect
This connects to 445 and after 5 milliseconds also to 139. It treats a netbios
session setup failure as equivalent as a TCP connect failure. So if 139 is
faster but fails the nb session setup, the 445 still has the chance to succeed.
(cherry picked from commit 35bbc2231760badaf0debc9f8f39ebdf00cfe8ad)
Volker Lendecke [Wed, 17 Nov 2010 15:56:28 +0000 (08:56 -0700)]
s3: Make winbind recover from a signing error
When winbind sees a signing error on the smb connection to a DC (for whatever
reason, our bug, network glitch, etc) it should recover properly. The "old"
code in clientgen.c just closed the socket in this case. This is the right
thing to do, this connection is spoiled anyway. The new, async code did not do
this so far, which led to the code in winbindd_cm.c not detect that we need to
reconnect.
Jeremy Allison [Tue, 27 Jul 2010 08:54:01 +0000 (01:54 -0700)]
Fix bug 7590 - offline login fails because winbind deletes cache on every startup.
Sync lib/tdb_validate.c with the change in current master.
Change tdb_validate_open() to always use O_RDWR instead of O_RDONLY,
as (from the bug report): "db_check() will always return failure for a read-only database.
Silently, without any log output, when _tdb_lockall() fails."
s3-winbind: Fix Bug #7568: Make sure cm_connect_lsa_tcp does not reset the secure channel.
This is an important fix as the following could and is happening:
* winbind authenticates a user via schannel secured netlogon samlogonex call,
current secure channel cred state is stored in winbind state, winbind
sucessfully decrypts session key from the info3
* winbind sets up a new schannel ncacn_ip_tcp lsa pipe (and thereby resets the
secure channel on the dc)
* subsequent samlogonex calls use the new secure channel creds on the dc to
encrypt info3 session key, while winbind tries to use old schannel creds for
decryption
s3-librpc: Fixed GUID_from_data_blob() with length of 32.
If we hit the case that the blob length is 32. The code goes to the end
of the function and generates a GUID with garbage.
So try to convert the blob to the GUID and return.
Günther Deschner [Fri, 14 May 2010 22:34:35 +0000 (00:34 +0200)]
s3-kerberos: temporary fix for ipv6 in print_kdc_line().
Currently no krb5 lib supports "kdc = ipv6 address" at all, so for now just fill
in just the kdc_name if we have it and let the krb5 lib figure out the
appropriate ipv6 address
Karolin Seeger [Wed, 12 May 2010 09:24:57 +0000 (11:24 +0200)]
s3-docs: Move -D option to the right paragraph in man winbindd.
Fix bug #7260 (Command line option documentation in wrong place in winbindd man
page.). Thanks to Ged Haywood <samba@jubileegroup.co.uk> for reporting!
Jeremy Allison [Thu, 9 Sep 2010 13:48:23 +0000 (15:48 +0200)]
Fix bug #7669.
Fix bug #7669 (buffer overflow in sid_parse() in Samba3 and dom_sid_parse in
Samba4).
CVE-2010-3069:
===========
Description
===========
All current released versions of Samba are vulnerable to
a buffer overrun vulnerability. The sid_parse() function
(and related dom_sid_parse() function in the source4 code)
do not correctly check their input lengths when reading a
binary representation of a Windows SID (Security ID). This
allows a malicious client to send a sid that can overflow
the stack variable that is being used to store the SID in the
Samba smbd server.
A connection to a file share is needed to exploit this
vulnerability, either authenticated or unauthenticated
(guest connection).
Roel van Meer [Fri, 26 Feb 2010 23:09:33 +0000 (15:09 -0800)]
Fix one of the valgrind warnings from bug #6814 - Fixes for problems reported by valgrind
The timeval passed to event_add_to_select_args() must be initialized
as event_add_to_select_args() uses a timeval_min() on this and next_event.
(cherry picked from commit a0254fa053cbaa8689de4f13893c50014085f7c8)
Jeff Layton [Tue, 26 Jan 2010 13:45:53 +0000 (08:45 -0500)]
mount.cifs: directly include sys/stat.h in mtab.c
This file is mysteriously getting included when built via the makefile,
but when you try to build mtab.o by hand it fails to build. Directly
include it to remove any ambiguity.
Jeff Layton [Tue, 26 Jan 2010 13:45:58 +0000 (08:45 -0500)]
mount.cifs: check for invalid characters in device name and mountpoint
It's apparently possible to corrupt the mtab if you pass embedded
newlines to addmntent. Apparently tabs are also a problem with certain
earlier glibc versions. Backslashes are also a minor issue apparently,
but we can't reasonably filter those.
Make sure that neither the devname or mountpoint contain any problematic
characters before allowing the mount to proceed.
Jeff Layton [Tue, 26 Jan 2010 13:45:58 +0000 (08:45 -0500)]
mount.cifs: take extra care that mountpoint isn't changed during mount
It's possible to trick mount.cifs into mounting onto the wrong directory
by replacing the mountpoint with a symlink to a directory. mount.cifs
attempts to check the validity of the mountpoint, but there's still a
possible race between those checks and the mount(2) syscall.
To guard against this, chdir to the mountpoint very early, and only deal
with it as "." from then on out.
Jeff Layton [Tue, 26 Jan 2010 13:45:58 +0000 (08:45 -0500)]
mount.cifs: don't allow it to be run as setuid root program
mount.cifs has been the subject of several "security" fire drills due to
distributions installing it as a setuid root program. This program has
not been properly audited for security and the Samba team highly
recommends that it not be installed as a setuid root program at this
time.
To make that abundantly clear, this patch forcibly disables the ability
for mount.cifs to run as a setuid root program. People are welcome to
trivially patch this out, but they do so at their own peril.
A security audit and redesign of this program is in progress and we hope
that we'll be able to remove this in the near future.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
The last 5 patches address bug #6853 (mount.cifs race that allows user to
replace mountpoint with a symlink).
(cherry picked from commit f94a377fb58f7b104aa633236f3391c9af6a7b12)
Jeff Layton [Tue, 26 Jan 2010 13:45:57 +0000 (08:45 -0500)]
mount.cifs: properly check for mount being in fstab when running setuid root (try#3)
This is the third attempt to clean up the checks when a setuid
mount.cifs is run by an unprivileged user. The main difference in this
patch from the last one is that it fixes a bug where the mount might
have failed if unnecessarily if CIFS_LEGACY_SETUID_CHECK was set.
When mount.cifs is installed setuid root and run as an unprivileged
user, it does some checks to limit how the mount is used. It checks that
the mountpoint is owned by the user doing the mount.
These checks however do not match those that /bin/mount does when it is
called by an unprivileged user. When /bin/mount is called by an
unprivileged user to do a mount, it checks that the mount in question is
in /etc/fstab, that it has the "user" option set, etc.
This means that it's currently not possible to set up user mounts the
standard way (by the admin, in /etc/fstab) and simultaneously protect
from an unprivileged user calling mount.cifs directly to mount a share
on any directory that that user owns.
Fix this by making the checks in mount.cifs match those of /bin/mount
itself. This is a necessary step to make mount.cifs safe to be installed
as a setuid binary, but not sufficient. For that, we'd need to give
mount.cifs a proper security audit.
Since some users may be depending on the legacy behavior, this patch
also adds the ability to build mount.cifs with the older behavior.
Based on a patch from Michael Karcher <samba@mkarcher.dialup.fu-berlin.de>.
I think this is the correct fix. It causes cups_job_submit to use
print_parse_jobid(), which I've moved into printing/lpq_parse.c (to allow the
link to work).
It turns out the old print_parse_jobid() was *broken*, in that the pjob
filename was set as an absolute path - not relative to the sharename (due to it
not going through the VFS calls).
This meant that the original code doing a strncmp on the first part of the
filename would always fail - it starts with a "/", not the relative pathname of
PRINT_SPOOL_PREFIX ("smbprn.").
This fix could fix some other mysterious printing bugs - probably the ones
Guenther noticed where job control fails on non-cups backends.
libwbclient: Re-Fix a bug that was fixed with e5741e27c4c
> r21878: Fix a bug with smbd serving a windows terminal server: If winbind
> decides smbd to be idle it might happen that smbd needs to do a winbind
> operation (for example sid2name) as non-root. This then fails to get the
> privileged pipe. When later on on the same connection another authentication
> request comes in, we try to do the CRAP auth via the non-privileged pipe.
>
> This adds a winbindd_priv_request_response() request that kills the existing
> winbind pipe connection if it's not privileged.
The fix for this was lost during the conversion to libwbclient.
Thanks to Ira Cooper <samba@ira.wakeful.net> for pointing this out!
s3:winbindd: fix problems with SIGCHLD handling (bug #7317)
The main problem is that we call CatchChild() within the
parent winbindd, which overwrites the signal handler
that was registered by winbindd_setup_sig_chld_handler().
That means winbindd_sig_chld_handler() and winbind_child_died()
are never triggered when a winbindd domain child dies.
As a result will get "broken pipe" for all requests to that domain.
To reduce the risk of similar bugs in future we call
CatchChild() in winbindd_reinit_after_fork() now.
We also use a full winbindd_reinit_after_fork() in the
cache validation child now instead instead of just resetting
the SIGCHLD handler by hand. This will also fix possible
tdb problems on systems without pread/pwrite and disabled mmap
as we now correctly reopen the tdb handle for the child.
s3:rpc_client: don't mix layers and keep a reference to cli_state in the caller
We should not rely on the backend to have a reference to the cli_state.
This will make it possible for the backend to set its cli_state reference
to NULL, when the transport is dead.