02 Aug, 2008
2 commits
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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
Acked-by: Eric Paris
Signed-off-by: Al Viro -
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
Signed-off-by: Al Viro
25 Jun, 2008
2 commits
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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
Signed-off-by: Al Viro -
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
Signed-off-by: Al Viro
17 May, 2008
1 commit
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Addresses http://bugzilla.kernel.org/show_bug.cgi?id=10663
Reporter: Daniel Marjamki
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Al Viro
28 Apr, 2008
6 commits
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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
Cc: "Eric W. Biederman"
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Al Viro -
Use msglen as the identifier.
kernel/audit.c:724:10: warning: symbol 'len' shadows an earlier one
kernel/audit.c:575:8: originally declared hereDon'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 herei 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 hereSigned-off-by: Harvey Harrison
Signed-off-by: Al Viro -
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
Signed-off-by: Al Viro -
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
Signed-off-by: Al Viro -
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
Signed-off-by: Al Viro -
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
Signed-off-by: Al Viro
19 Apr, 2008
2 commits
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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_matchinstad of (respectively) :
selinux_audit_rule_init
selinux_audit_rule_free
audit_rule_has_selinux
selinux_audit_rule_matchSigned-off-by: Casey Schaufler
Signed-off-by: Ahmed S. Darwish
Acked-by: James Morris -
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
Signed-off-by: Ahmed S. Darwish
Acked-by: James Morris
Reviewed-by: Paul Moore
29 Mar, 2008
1 commit
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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
Acked-by: Randy Dunlap
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Mar, 2008
1 commit
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From: Pavel Emelyanov
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
Signed-off-by: Pavel Emelyanov
Acked-by: Eric Paris
Signed-off-by: David S. Miller
01 Mar, 2008
2 commits
-
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
Signed-off-by: Al Viro -
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
15 Feb, 2008
2 commits
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d_path() is used on a pair. Lets use a struct path to
reflect this.[akpm@linux-foundation.org: fix build in mm/memory.c]
Signed-off-by: Jan Blunck
Acked-by: Bryan Wu
Acked-by: Christoph Hellwig
Cc: Al Viro
Cc: "J. Bruce Fields"
Cc: Neil Brown
Cc: Michael Halcrow
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Christoph Hellwig
Cc: Al Viro
Cc: "J. Bruce Fields"
Cc: Neil Brown
Cc: Stephen Smalley
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Feb, 2008
8 commits
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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
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Complement va_copy() with va_end().
Signed-off-by: Richard Knutsson
Cc: Al Viro
Signed-off-by: Andrew Morton -
kernel/audit.c: In function 'audit_log_start':
kernel/audit.c:1133: warning: 'serial' may be used uninitialized in this functionCc: Al Viro
Signed-off-by: Andrew Morton -
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
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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 functionSigned-off-by: Eric Paris
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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
-
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 7.5ksingle arguments larger than 7.5k in length are split into multiple records
and can be identified as aX[Y]=Signed-off-by: Eric Paris
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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
Signed-off-by: Eric Paris
01 Feb, 2008
1 commit
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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
Acked-by: James Morris
Signed-off-by: David S. Miller
21 Oct, 2007
1 commit
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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
19 Oct, 2007
1 commit
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Just removing white space at the end of lines.
Signed-off-by: Daniel Walker
Cc: David Woodhouse
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Oct, 2007
2 commits
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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
Acked-by: Alexey Kuznetsov
Signed-off-by: David S. Miller -
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
Signed-off-by: David S. Miller
18 Jul, 2007
1 commit
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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
Acked-by: Nigel Cunningham
Cc: Pavel Machek
Cc: Oleg Nesterov
Cc: Gautham R Shenoy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Jul, 2007
1 commit
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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
Cc: Al Viro
Cc: Alan Cox
Cc: Paul Fulghum
Cc: Casey Schaufler
Cc: Steve Grubb
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 May, 2007
1 commit
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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
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Apr, 2007
3 commits
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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
Signed-off-by: David S. Miller -
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
Signed-off-by: David S. Miller -
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
Signed-off-by: David S. Miller
18 Feb, 2007
1 commit
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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
Signed-off-by: Al Viro
08 Dec, 2006
1 commit
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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
Cc: "Rafael J. Wysocki"
Cc: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
