audit_log_d_path had spaces in the strings which would be emitted on the
error paths. This patch simply replaces those spaces with an _ or removes
the needless spaces entirely.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
AUDIT_USER_TTY, like all other messages sent from user-space, is sent
NUL-terminated. Unlike other user-space audit messages, which come only
from trusted sources, AUDIT_USER_TTY messages are processed using
audit_log_n_untrustedstring().
This patch modifies AUDIT_USER_TTY handling to ignore the trailing NUL
and use the "quoted_string" representation of the message if possible.
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
currently audit_log_n_untrustedstring() uses audit_string_contains_control()
to check if the 'string' has any control characters. If the 'string' has an
embedded NULL audit_string_contains_control() will return that the data has
no control characters and will then pass the string to audit_log_n_string
with the total length, not the length up to the first NULL.
audit_log_n_string() does a memcpy of the entire length and so the actual
audit record emitted may then contain a NULL and then whatever random memory
is after the NULL.
Since we want to log the entire octet stream (if we can't trust the data
to be a string we can't trust that a NULL isn't actually a part of it)
we should just consider NULL as a control character. If the caller is
certain they want to stop at the first NULL they should be using
audit_log_untrustedstring.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently audit=0 on the kernel command line does absolutely nothing.
Audit always loads and always uses its resources such as creating the
kernel netlink socket. This patch causes audit=0 to actually disable
audit. Audit will use no resources and starting the userspace auditd
daemon will not cause the kernel audit system to activate.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When the "status_get->mask" is "AUDIT_STATUS_RATE_LIMIT || AUDIT_STATUS_BACKLOG_LIMIT".
If "audit_set_rate_limit" fails and "audit_set_backlog_limit" succeeds, the "err" value
will be greater than or equal to 0. It will miss the failure of rate set.
Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hello,
According to my understanding there is an off-by-one bug in the
function:
audit_string_contains_control()
in:
kernel/audit.c
Patch is included.
I do not know from how many places the function is called from, but for
example, SELinux Access Vector Cache tries to log untrusted filenames via
call path:
avc_audit()
audit_log_untrustedstring()
audit_log_n_untrustedstring()
audit_string_contains_control()
If audit_string_contains_control() detects control characters, then the
string is hex-encoded. But the hex=0x7f dec=127, DEL-character, is not
detected.
I guess this could have at least some minor security implications, since a
user can create a filename with 0x7f in it, causing logged filename to
possibly look different when someone reads it on the terminal.
Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The second argument "type" is not used in audit_filter_user(), so I think that type can be removed. If I'm wrong, please tell me.
Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The first argument "nlh->nlmsg_type" of audit_receive_filter() should be modified to "msg_type" in audit_receive_msg().
Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=10663
Reporter: Daniel Marjamki <danielm77@spray.se>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The pid to lookup a task by is passed inside audit code via netlink message.
Thanks to Denis Lunev, netlink packets are now (since 2.6.24) _always_
processed in the context of the sending task. So this is correct to lookup
the task with find_task_by_vpid() here.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Use msglen as the identifier.
kernel/audit.c:724:10: warning: symbol 'len' shadows an earlier one
kernel/audit.c:575:8: originally declared here
Don't use ino_f to check the inode field at the end of the functions.
kernel/auditfilter.c:429:22: warning: symbol 'f' shadows an earlier one
kernel/auditfilter.c:420:21: originally declared here
kernel/auditfilter.c:542:22: warning: symbol 'f' shadows an earlier one
kernel/auditfilter.c:529:21: originally declared here
i always used as a counter for a for loop and initialized to zero before
use. Eliminate the inner i variables.
kernel/auditsc.c:1295:8: warning: symbol 'i' shadows an earlier one
kernel/auditsc.c:1152:6: originally declared here
kernel/auditsc.c:1320:7: warning: symbol 'i' shadows an earlier one
kernel/auditsc.c:1152:6: originally declared here
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch standardized the string auditing interfaces. No userspace
changes will be visible and this is all just cleanup and consistancy
work. We have the following string audit interfaces to use:
void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len);
void audit_log_n_string(struct audit_buffer *ab, const char *buf, size_t n);
void audit_log_string(struct audit_buffer *ab, const char *buf);
void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, size_t n);
void audit_log_untrustedstring(struct audit_buffer *ab, const char *string);
This may be the first step to possibly fixing some of the issues that
people have with the string output from the kernel audit system. But we
still don't have an agreed upon solution to that problem.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A deadlock is possible between kauditd and auditd under load if auditd
receives a signal. When auditd receives a signal it sends a netlink
message to the kernel asking for information about the sender of the
signal. In that same context the audit system will attempt to send a
netlink message back to the userspace auditd. If kauditd has already
filled the socket buffer (see netlink_attachskb()) auditd will now put
itself to sleep waiting for room to send the message. Since auditd is
responsible for draining that socket we have a deadlock. The fix, since
the response from the kernel does not need to be synchronous is to send
the signal information back to auditd in a separate thread. And thus
auditd can continue to drain the audit queue normally.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch causes the kernel audit subsystem to store up to
audit_backlog_limit messages for use by auditd if it ever appears
sometime in the future in userspace. This is useful to collect audit
messages during bootup and even when auditd is stopped. This is NOT a
reliable mechanism, it does not ever call audit_panic, nor should it.
audit_log_lost()/audit_panic() are called during the normal delivery
mechanism. The messages are still sent to printk/syslog as usual and if
too many messages appear to be queued they will be silently discarded.
I liked doing it by default, but this patch only uses the queue in
question if it was booted with audit=1 or if the kernel was built
enabling audit by default.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Previously I added sessionid output to all audit messages where it was
available but we still didn't know the sessionid of the sender of
netlink messages. This patch adds that information to netlink messages
so we can audit who sent netlink messages.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Convert Audit to use the new LSM Audit hooks instead of
the exported SELinux interface.
Basically, use:
security_audit_rule_init
secuirty_audit_rule_free
security_audit_rule_known
security_audit_rule_match
instad of (respectively) :
selinux_audit_rule_init
selinux_audit_rule_free
audit_rule_has_selinux
selinux_audit_rule_match
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Stop using the following exported SELinux interfaces:
selinux_get_inode_sid(inode, sid)
selinux_get_ipc_sid(ipcp, sid)
selinux_get_task_sid(tsk, sid)
selinux_sid_to_string(sid, ctx, len)
kfree(ctx)
and use following generic LSM equivalents respectively:
security_inode_getsecid(inode, secid)
security_ipc_getsecid*(ipcp, secid)
security_task_getsecid(tsk, secid)
security_sid_to_secctx(sid, ctx, len)
security_release_secctx(ctx, len)
Call security_release_secctx only if security_secid_to_secctx
succeeded.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Silence two kerneldoc warnings.
Warning(kernel/audit.c:1276): No description found for parameter 'string'
Warning(kernel/audit.c:1276): No description found for parameter 'len'
[also fix a typo for bonus points]
Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
From: Pavel Emelyanov <xemul@openvz.org>
This patch is based on the one from Thomas.
The kauditd_thread() calls the netlink_unicast() and passes
the audit_pid to it. The audit_pid, in turn, is received from
the user space and the tool (I've checked the audit v1.6.9)
uses getpid() to pass one in the kernel. Besides, this tool
doesn't bind the netlink socket to this id, but simply creates
it allowing the kernel to auto-bind one.
That's the preamble.
The problem is that netlink_autobind() _does_not_ guarantees
that the socket will be auto-bound to the current pid. Instead
it uses the current pid as a hint to start looking for a free
id. So, in case of conflict, the audit messages can be sent
to a wrong socket. This can happen (it's unlikely, but can be)
in case some task opens more than one netlink sockets and then
the audit one starts - in this case the audit's pid can be busy
and its socket will be bound to another id.
The proposal is to introduce an audit_nlk_pid in audit subsys,
that will point to the netlink socket to send packets to. It
will most often be equal to audit_pid. The socket id can be
got from the skb's netlink CB right in the audit_receive_msg.
The audit_nlk_pid reset to 0 is not required, since all the
decisions are taken based on audit_pid value only.
Later, if the audit tools will bind the socket themselves, the
kernel will have to provide a way to setup the audit_nlk_pid
as well.
A good side effect of this patch is that audit_pid can later
be converted to struct pid, as it is not longer safe to use
pid_t-s in the presence of pid namespaces. But audit code still
uses the tgid from task_struct in the audit_signal_info and in
the audit_filter_syscall.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hi,
While we are looking at the printk issue, I see that its printk'ing the EOE
(end of event) records which is really not something that we need in syslog.
Its really intended for the realtime audit event stream handled by the audit
daemon. So, lets avoid printk'ing that record type.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
On the latest kernels if one was to load about 15 rules, set the failure
state to panic, and then run service auditd stop the kernel will panic.
This is because auditd stops, then the script deletes all of the rules.
These deletions are sent as audit messages out of the printk kernel
interface which is already known to be lossy. These will overun the
default kernel rate limiting (10 really fast messages) and will call
audit_panic(). The same effect can happen if a slew of avc's come
through while auditd is stopped.
This can be fixed a number of ways but this patch fixes the problem by
just not panicing if auditd is not running. We know printk is lossy and
if the user chooses to set the failure mode to panic and tries to use
printk we can't make any promises no matter how hard we try, so why try?
At least in this way we continue to get lost message accounting and will
eventually know that things went bad.
The other change is to add a new call to audit_log_lost() if auditd
disappears. We already pulled the skb off the queue and couldn't send
it so that message is lost. At least this way we will account for the
last message and panic if the machine is configured to panic. This code
path should only be run if auditd dies for unforeseen reasons. If
auditd closes correctly audit_pid will get set to 0 and we won't walk
this code path.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
d_path() is used on a <dentry,vfsmount> pair. Lets use a struct path to
reflect this.
[akpm@linux-foundation.org: fix build in mm/memory.c]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Bryan Wu <bryan.wu@analog.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
audit_log_d_path() is a d_path() wrapper that is used by the audit code. To
use a struct path in audit_log_d_path() I need to embed it into struct
avc_audit_data.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
some printk messages from the audit system can become excessive. This
patch ratelimits those messages. It was found that messages, such as
the audit backlog lost printk message could flood the logs to the point
that a machine could take an nmi watchdog hit or otherwise become
unresponsive.
Signed-off-by: Eric Paris <eparis@redhat.com>
Complement va_copy() with va_end().
Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kernel/audit.c: In function 'audit_log_start':
kernel/audit.c:1133: warning: 'serial' may be used uninitialized in this function
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Disabling audit at runtime by auditctl doesn't mean that we can
stop allocating contexts for new processes; we don't want to miss them
when that sucker is reenabled.
(based on work from Al Viro in the RHEL kernel series)
Signed-off-by: Eric Paris <eparis@redhat.com>
generally clean up audit_receive_msg() don't free random memory if
selinux_sid_to_string fails for some reason. Move generic auditing
to a helper function
Signed-off-by: Eric Paris <eparis@redhat.com>
Some audit messages (namely configuration changes) are still emitted even if
the audit subsystem has been explicitly disabled. This patch turns those
messages off as well.
Signed-off-by: Eric Paris <eparis@redhat.com>
execve arguments can be quite large. There is no limit on the number of
arguments and a 4G limit on the size of an argument.
this patch prints those aruguments in bite sized pieces. a userspace size
limitation of 8k was discovered so this keeps messages around 7.5k
single arguments larger than 7.5k in length are split into multiple records
and can be identified as aX[Y]=
Signed-off-by: Eric Paris <eparis@redhat.com>
Currently audit drops the audit type when an audit message goes through
printk instead of the audit deamon. This is a minor annoyance in
that the audit type is no longer part of the message and the information
the audit type conveys needs to be carried in, or derived from the
message data.
The attached patch includes the type number as part of the printk.
Admittedly it isn't the type name that the audit deamon provides but I
think this is better than dropping the type completely.
Signed-pff-by: John Johansen <jjohansen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
The recent UDP patch exposed this bug in the audit code. It
was calling pskb_expand_head without increasing skb->truesize.
The caller of pskb_expand_head needs to do so because that function
is designed to be called in places where truesize is already fixed
and therefore it doesn't update its value.
Because the audit system is using it in a place where the truesize
has not yet been fixed, it needs to update its value manually.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Just removing white space at the end of lines.
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch make processing netlink user -> kernel messages synchronious.
This change was inspired by the talk with Alexey Kuznetsov about current
netlink messages processing. He says that he was badly wrong when introduced
asynchronious user -> kernel communication.
The call netlink_unicast is the only path to send message to the kernel
netlink socket. But, unfortunately, it is also used to send data to the
user.
Before this change the user message has been attached to the socket queue
and sk->sk_data_ready was called. The process has been blocked until all
pending messages were processed. The bad thing is that this processing
may occur in the arbitrary process context.
This patch changes nlk->data_ready callback to get 1 skb and force packet
processing right in the netlink_unicast.
Kernel -> user path in netlink_unicast remains untouched.
EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock
drop, but the process remains in the cycle until the message will be fully
processed. So, there is no need to use this kludges now.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each netlink socket will live in exactly one network namespace,
this includes the controlling kernel sockets.
This patch updates all of the existing netlink protocols
to only support the initial network namespace. Request
by clients in other namespaces will get -ECONREFUSED.
As they would if the kernel did not have the support for
that netlink protocol compiled in.
As each netlink protocol is updated to be multiple network
namespace safe it can register multiple kernel sockets
to acquire a presence in the rest of the network namespaces.
The implementation in af_netlink is a simple filter implementation
at hash table insertion and hash table look up time.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves. This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.
It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.
The patch causes all kernel threads to be nonfreezable by default (ie. to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE. It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear. Additionally, it updates documentation to
describe the freezing of tasks more accurately.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Following the programming advice laid down in the gcc manual, make
sure the case "..." operator has spaces on either side.
According to:
http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Case-Ranges.html#Case-Ranges:
"Be careful: Write spaces around the ..., for otherwise it may be
parsed wrong when you use it with integer values."
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch cb_lock to mutex and allow netlink kernel users to override it
with a subsystem specific mutex for consistent locking in dump callbacks.
All netlink_dump_start users have been audited not to rely on any
side-effects of the previously used spinlock.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the common "(struct nlmsghdr *)skb->data" sequence, so that we reduce the
number of direct accesses to skb->data and for consistency with all the other
cast skb member helpers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following patch adds a new mode to the audit system. It uses the
audit_enabled config option to introduce the idea of audit enabled, but
configuration is immutable. Any attempt to change the configuration
while in this mode is audited. To change the audit rules, you'd need to
reboot the machine.
To use this option, you'd need a modified version of auditctl and use "-e 2".
This is intended to go at the end of the audit.rules file for people that
want an immutable configuration.
This patch also adds "res=" to a number of configuration commands that did not
have it before.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.
[akpm@osdl.org: fix ueagle driver]
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Squash this warning:
kernel/audit.c: In function 'kauditd_thread':
kernel/audit.c:367: warning: no return statement in function returning non-void
We might as test kthread_should_stop(), although it's not very pointful at
present.
The code which starts this thread looks racy - the kernel could start multiple
threads.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Rename selinux_ctxid_to_string to selinux_sid_to_string to be
consistent with other interfaces.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add sanity checks for NULL audit_buffer consistent with other
audit_log* routines.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Always initialize the audit_inode_hash[] so we don't oops on list rules.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch encapsulates the usage of eff_cap (in netlink_skb_params) within
the security framework by extending security_netlink_recv to include a required
capability parameter and converting all direct usage of eff_caps outside
of the lsm modules to use the interface. It also updates the SELinux
implementation of the security_netlink_send and security_netlink_recv
hooks to take advantage of the sid in the netlink_skb_params struct.
This also enables SELinux to perform auditing of netlink capability checks.
Please apply, for 2.6.18 if possible.
Signed-off-by: Darrel Goeddel <dgoeddel@trustedcs.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
locking init cleanups:
- convert " = SPIN_LOCK_UNLOCKED" to spin_lock_init() or DEFINE_SPINLOCK()
- convert rwlocks in a similar manner
this patch was generated automatically.
Motivation:
- cleanliness
- lockdep needs control of lock initialization, which the open-coded
variants do not give
- it's also useful for -rt and for lock debugging in general
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In this implementation, audit registers inotify watches on the parent
directories of paths specified in audit rules. When audit's inotify
event handler is called, it updates any affected rules based on the
filesystem event. If the parent directory is renamed, removed, or its
filesystem is unmounted, audit removes all rules referencing that
inotify watch.
To keep things simple, this implementation limits location-based
auditing to the directory entries in an existing directory. Given
a path-based rule for /foo/bar/passwd, the following table applies:
passwd modified -- audit event logged
passwd replaced -- audit event logged, rules list updated
bar renamed -- rule removed
foo renamed -- untracked, meaning that the rule now applies to
the new location
Audit users typically want to have many rules referencing filesystem
objects, which can significantly impact filtering performance. This
patch also adds an inode-number-based rule hash to mitigate this
situation.
The patch is relative to the audit git tree:
http://kernel.org/git/?p=linux/kernel/git/viro/audit-current.git;a=summary
and uses the inotify kernel API:
http://lkml.org/lkml/2006/6/1/145
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Just a few minor proposed updates. Only the last one will
actually affect behavior. The rest are just misleading
code.
Several AUDIT_SET functions return 'old' value, but only
return value <0 is checked for. So just return 0.
propagate audit_set_rate_limit and audit_set_backlog_limit
error values
In audit_buffer_free, the audit_freelist_count was being
incremented even when we discard the return buffer, so
audit_freelist_count can end up wrong. This could cause
the actual freelist to shrink over time, eventually
threatening to degrate audit performance.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We should not send a pile of replies while holding audit_netlink_mutex
since we hold the same mutex when we receive commands. As the result,
we can get blocked while sending and sit there holding the mutex while
auditctl is unable to send the next command and get around to receiving
what we'd sent.
Solution: create skb and put them into a queue instead of sending;
once we are done, send what we've got on the list. The former can
be done synchronously while we are handling AUDIT_LIST or AUDIT_LIST_RULES;
we are holding audit_netlink_mutex at that point. The latter is done
asynchronously and without messing with audit_netlink_mutex.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hi,
The patch below builds upon the patch sent earlier and adds subject label to
all audit events generated via the netlink interface. It also cleans up a few
other minor things.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The below patch should be applied after the inode and ipc sid patches.
This patch is a reworking of Tim's patch that has been updated to match
the inode and ipc patches since its similar.
[updated:
> Stephen Smalley also wanted to change a variable from isec to tsec in the
> user sid patch. ]
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch provides the ability to filter audit messages based on the
elements of the process' SELinux context (user, role, type, mls sensitivity,
and mls clearance). It uses the new interfaces from selinux to opaquely
store information related to the selinux context and to filter based on that
information. It also uses the callback mechanism provided by selinux to
refresh the information when a new policy is loaded.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The boot cmdline is parsed in parse_early_param() and
parse_args(,unknown_bootoption).
And __setup() is used in obsolete_checksetup().
start_kernel()
-> parse_args()
-> unknown_bootoption()
-> obsolete_checksetup()
If __setup()'s callback (->setup_func()) returns 1 in
obsolete_checksetup(), obsolete_checksetup() thinks a parameter was
handled.
If ->setup_func() returns 0, obsolete_checksetup() tries other
->setup_func(). If all ->setup_func() that matched a parameter returns 0,
a parameter is seted to argv_init[].
Then, when runing /sbin/init or init=app, argv_init[] is passed to the app.
If the app doesn't ignore those arguments, it will warning and exit.
This patch fixes a wrong usage of it, however fixes obvious one only.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make audit_init() failure path handle situations where the audit_panic()
action is not AUDIT_FAIL_PANIC (default is AUDIT_FAIL_PRINTK). Other uses
of audit_sock are not reached unless audit's netlink message handler is
properly registered. Bug noticed by Peter Staubach.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hi,
This is a trivial patch that enables the possibility of using some auditing
functions within loadable kernel modules (ie. inside a Linux Security Module).
_
Make the audit_log_start, audit_log_end, audit_format and audit_log
interfaces available to Loadable Kernel Modules, thus making possible
the usage of the audit framework inside LSMs, etc.
Signed-off-by: <Lorenzo Hernández García-Hierro <lorenzo@gnu.org>>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This fixes the per-user and per-message-type filtering when syscall
auditing isn't enabled.
[AV: folded followup fix from the same author]
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch extends existing audit records with subject/object context
information. Audit records associated with filesystem inodes, ipc, and
tasks now contain SELinux label information in the field "subj" if the
item is performing the action, or in "obj" if the item is the receiver
of an action.
These labels are collected via hooks in SELinux and appended to the
appropriate record in the audit code.
This additional information is required for Common Criteria Labeled
Security Protection Profile (LSPP).
[AV: fixed kmalloc flags use]
[folded leak fixes]
[folded cleanup from akpm (kfree(NULL)]
[folded audit_inode_context() leak fix]
[folded akpm's fix for audit_ipc_perm() definition in case of !CONFIG_AUDIT]
Signed-off-by: Dustin Kirkland <dustin.kirkland@us.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
- Add a new, 5th filter called "exclude".
- And add a new field AUDIT_MSGTYPE.
- Define a new function audit_filter_exclude() that takes a message type
as input and examines all rules in the filter. It returns '1' if the
message is to be excluded, and '0' otherwise.
- Call the audit_filter_exclude() function near the top of
audit_log_start() just after asserting audit_initialized. If the
message type is not to be audited, return NULL very early, before
doing a lot of work.
[combined with followup fix for bug in original patch, Nov 4, same author]
[combined with later renaming AUDIT_FILTER_EXCLUDE->AUDIT_FILTER_TYPE
and audit_filter_exclude() -> audit_filter_type()]
Signed-off-by: Dustin Kirkland <dustin.kirkland@us.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The attached patch updates various items for the new user space
messages. Please apply.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
- add kerneldoc for non-static functions;
- don't init static data to 0;
- limit lines to < 80 columns;
- fix long-format style;
- delete whitespace at end of some lines;
(chrisw: resend and update to current audit-2.6 tree)
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
EDAC requires a way to scrub memory if an ECC error is found and the chipset
does not do the work automatically. That means rewriting memory locations
atomically with respect to all CPUs _and_ bus masters. That means we can't
use atomic_add(foo, 0) as it gets optimised for non-SMP
This adds a function to include/asm-foo/atomic.h for the platforms currently
supported which implements a scrub of a mapped block.
It also adjusts a few other files include order where atomic.h is included
before types.h as this now causes an error as atomic_scrub uses u32.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the following cleanups:
- make needlessly global functions static
- every file should include the headers containing the prototypes for
it's global functions
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kauditd was causing suspends to fail because it refused to freeze. Adding
a try_to_freeze() to its sleep loop solves the issue.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Acked-by: Pavel Machek <pavel@suse.cz>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- added typedef unsigned int __nocast gfp_t;
- replaced __nocast uses for gfp flags with gfp_t - it gives exactly
the same warnings as far as sparse is concerned, doesn't change
generated code (from gcc point of view we replaced unsigned int with
typedef) and documents what's going on far better.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Remove bogus code for compiling netlink as module
- Add module refcounting support for modules implementing a netlink
protocol
- Add support for autoloading modules that implement a netlink protocol
as soon as someone opens a socket for that protocol
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following patch against audit.81 prevents duplicate syscall rules in
a given filter list by walking the list on each rule add.
I also removed the unused struct audit_entry in audit.c and made the
static inlines in auditsc.c consistent.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
... by generating serial numbers only if an audit context is actually
_used_, rather than doing so at syscall entry even when the context
isn't necessarily marked auditable.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Fix the sparse warning "implicit cast to nocast type"
Signed-off-by: Victor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
We force a rate-limit on auditable events by making them wait for space
on the backlog queue. However, if auditd really is AWOL then this could
potentially bring the entire system to a halt, depending on the audit
rules in effect.
Firstly, make sure the wait time is honoured correctly -- it's the
maximum time the process should wait, rather than the time to wait
_each_ time round the loop. We were getting re-woken _each_ time a
packet was dequeued, and the timeout was being restarted each time.
Secondly, reset the wait time after audit_panic() is called. In general
this will be reset to zero, to allow progress to be made. If the system
is configured to _actually_ panic on audit_panic() then that will
already have happened; otherwise we know that audit records are being
lost anyway.
These two tunables can't be exposed via AUDIT_GET and AUDIT_SET because
those aren't particularly well-designed. It probably should have been
done by sysctls or sysfs anyway -- one for a later patch.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Don't look up the task by its pid and then use the syscall filtering
helper. Just implement our own filter helper which operates solely on
the information in the netlink_skb_parms.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Add a gfp_mask to audit_log_start() and audit_log(), to reduce the
amount of GFP_ATOMIC allocation -- most of it doesn't need to be
GFP_ATOMIC. Also if the mask includes __GFP_WAIT, then wait up to
60 seconds for the auditd backlog to clear instead of immediately
abandoning the message.
The timeout should probably be made configurable, but for now it'll
suffice that it only happens if auditd is actually running.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
If we have enough rules to fill the netlink buffer space, it'll
deadlock because auditctl isn't ever actually going to read from the
socket until we return, and we aren't going to return until it
reads... so we spawn a kernel thread to spew out the list and then
exit.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Turn the field from a bitmask to an enumeration and add a list to allow
filtering of messages generated by userspace. We also define a list for
file system watches in anticipation of that feature.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
These changes make processing of audit logs easier. Based on a patch
from Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Move audit_serial() into audit.c and use it to generate serial numbers
on messages even when there is no audit context from syscall auditing.
This allows us to disambiguate audit records when more than one is
generated in the same millisecond.
Based on a patch by Steve Grubb after he observed the problem.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
The attached patch changes all occurrences of loginuid to auid. It also
changes everything to %u that is an unsigned type.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
The original AVC_USER message wasn't consolidated with the new range of
user messages. The attached patch fixes the kernel so the old messages
work again.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
The limit on the number of outstanding audit messages was inadvertently
removed with the switch to queuing skbs directly for sending by a kernel
thread. Put it back again.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
netlink_unicast() will attempt to reallocate and will free messages if
the socket's rcvbuf limit is reached unless we give it an infinite
timeout. So do that, from a kernel thread which is dedicated to spewing
stuff up the netlink socket.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
* If vsnprintf returns -1, it will mess up the sk buffer space accounting.
This is fixed by not calling skb_put with bogus len values.
* audit_log_hex was a loop that called audit_log_vformat with %02X for each
character. This is very inefficient since conversion from unsigned character
to Ascii representation is essentially masking, shifting, and byte lookups.
Also, the length of the converted string is well known - it's twice the
original. Fixed by rewriting the function.
* audit_log_untrustedstring had no comments. This makes it hard for
someone to understand what the string format will be.
* audit_log_d_path was never fixed to use untrustedstring. This could mess
up user space parsers. This was fixed to make a temp buffer, call d_path,
and log temp buffer using untrustedstring.
From: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
It's silly to have to add explicit entries for new userspace messages
as we invent them. Just treat all messages in the user range the same.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Der... if you use max_t it helps if you give it a type.
Note to self: Always just apply the tested patches, don't try to port
them by hand. You're not clever enough.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
I'm going through the kernel code and have a patch that corrects
several spelling errors in comments.
From: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This patch adds more messages types to the audit subsystem so that audit
analysis is quicker, intuitive, and more useful.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
---
I forgot one type in the big patch. I need to add one for user space
originating SE Linux avc messages. This is used by dbus and nscd.
-Steve
---
Updated to 2.6.12-rc4-mm1.
-dwmw2
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Otherwise, we will be repeatedly reallocating, even if we're only
adding a few bytes at a time. Pointed out by Steve Grubb.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Add audit_log_type to allow callers to specify type and pid when logging.
Convert audit_log to wrapper around audit_log_type. Could have
converted all audit_log callers directly, but common case is default
of type AUDIT_KERNEL and pid 0. Update audit_log_start to take type
and pid values when creating a new audit_buffer. Move sequences that
did audit_log_start, audit_log_format, audit_set_type, audit_log_end,
to simply call audit_log_type directly. This obsoletes audit_set_type
and audit_set_pid, so remove them.
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Remove code conditionally dependent on CONFIG_AUDITSYSCALL from audit.c.
Move these dependencies to audit.h with the rest.
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Audit now actually requires netlink. So make it depend on CONFIG_NET,
and remove the inline dependencies on CONFIG_NET.
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Let audit_expand() know how much it's expected to grow the buffer, in
the case that we have that information to hand.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
We were setting nlmsg_len to skb->len, but we should be subtracting
the size of the header.
From: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Drop the use of a tmp buffer in the audit_buffer, and just buffer
directly to the skb. All header data that was temporarily stored in
the audit_buffer can now be stored directly in the netlink header in
the skb. Resize skb as needed. This eliminates the extra copy (and
the audit_log_move function which was responsible for copying).
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Introduce audit_expand and make the audit_buffer use a dynamic buffer
which can be resized. When audit buffer is moved to skb it will not
be fragmented across skb's, so we can eliminate the sklist in the
audit_buffer. During audit_log_move, we simply copy the full buffer
into a single skb, and then audit_log_drain sends it on.
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
shutdown credential information. It creates a new message type
AUDIT_TERM_INFO, which is used by the audit daemon to query who issued the
shutdown.
It requires the placement of a hook function that gathers the information. The
hook is after the DAC & MAC checks and before the function returns. Racing
threads could overwrite the uid & pid - but they would have to be root and
have policy that allows signalling the audit daemon. That should be a
manageable risk.
The userspace component will be released later in audit 0.7.2. When it
receives the TERM signal, it queries the kernel for shutdown information.
When it receives it, it writes the message and exits. The message looks
like this:
type=DAEMON msg=auditd(1114551182.000) auditd normal halt, sending pid=2650
uid=525, auditd pid=1685
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Let's recap the problem. The current asynchronous netlink kernel
message processing is vulnerable to these attacks:
1) Hit and run: Attacker sends one or more messages and then exits
before they're processed. This may confuse/disable the next netlink
user that gets the netlink address of the attacker since it may
receive the responses to the attacker's messages.
Proposed solutions:
a) Synchronous processing.
b) Stream mode socket.
c) Restrict/prohibit binding.
2) Starvation: Because various netlink rcv functions were written
to not return until all messages have been processed on a socket,
it is possible for these functions to execute for an arbitrarily
long period of time. If this is successfully exploited it could
also be used to hold rtnl forever.
Proposed solutions:
a) Synchronous processing.
b) Stream mode socket.
Firstly let's cross off solution c). It only solves the first
problem and it has user-visible impacts. In particular, it'll
break user space applications that expect to bind or communicate
with specific netlink addresses (pid's).
So we're left with a choice of synchronous processing versus
SOCK_STREAM for netlink.
For the moment I'm sticking with the synchronous approach as
suggested by Alexey since it's simpler and I'd rather spend
my time working on other things.
However, it does have a number of deficiencies compared to the
stream mode solution:
1) User-space to user-space netlink communication is still vulnerable.
2) Inefficient use of resources. This is especially true for rtnetlink
since the lock is shared with other users such as networking drivers.
The latter could hold the rtnl while communicating with hardware which
causes the rtnetlink user to wait when it could be doing other things.
3) It is still possible to DoS all netlink users by flooding the kernel
netlink receive queue. The attacker simply fills the receive socket
with a single netlink message that fills up the entire queue. The
attacker then continues to call sendmsg with the same message in a loop.
Point 3) can be countered by retransmissions in user-space code, however
it is pretty messy.
In light of these problems (in particular, point 3), we should implement
stream mode netlink at some point. In the mean time, here is a patch
that implements synchronous processing.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
When adding more formatted audit data to an skb for delivery to userspace,
the kernel will attempt to reuse an skb that has spare room. However, if
the audit message has already been fragmented to multiple skb's, the search
for spare room in the skb uses the head of the list. This will corrupt the
audit message with trailing bytes being placed midway through the stream.
Fix is to look at the end of the list.
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
If netlink_unicast() fails, requeue the skb back at the head of the queue
it just came from, instead of the tail. And do so unless we've exceeded
the audit_backlog limit; not according to some other arbitrary limit.
From: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Most audit control messages are sent over netlink.In order to properly
log the identity of the sender of audit control messages, we would like
to add the loginuid to the netlink_creds structure, as per the attached
patch.
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
They don't seem to work correctly (investigation ongoing), but we don't
actually need to do it anyway.
Patch from Peter Martuccelli <peterm@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Attached is a patch that corrects a signed/unsigned warning. I also noticed
that we needlessly init serial to 0. That only needs to occur if the kernel
was compiled without the audit system.
-Steve Grubb
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
kernel/audit.c: In function `audit_log_untrustedstring':
kernel/audit.c:736: warning: comparison is always false due to limited range of data type
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
We log strings from userspace, such as arguments to open(). These could
be formatted to contain \n followed by fake audit log entries. Provide
a function for logging such strings, which gives a hex dump when the
string contains anything but basic printable ASCII characters. Use it
for logging filenames.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Eric Paris