linux-toradex.git/kernel/audit.c, branch v2.6.26-rc3

[patch 2/2] Use find_task_by_vpid in audit code

2008-04-28T10:28:30+00:00

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

[PATCH 2/2] audit: fix sparse shadowed variable warnings

2008-04-28T10:28:17+00:00

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 
Signed-off-by: Al Viro

Audit: standardize string audit interfaces

2008-04-28T10:19:22+00:00

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

Audit: stop deadlock from signals under load

2008-04-28T10:19:13+00:00

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

Audit: save audit_backlog_limit audit messages in case auditd comes back

2008-04-28T10:19:04+00:00

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

Audit: collect sessionid in netlink messages

2008-04-28T10:18:03+00:00

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

Audit: internally use the new LSM audit hooks

2008-04-18T23:52:37+00:00

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 
Signed-off-by: Ahmed S. Darwish 
Acked-by: James Morris

Audit: use new LSM hooks instead of SELinux exports

2008-04-18T23:52:34+00:00

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

audit: silence two kerneldoc warnings in kernel/audit.c

2008-03-28T21:45:21+00:00

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

audit: netlink socket can be auto-bound to pid other than current->pid (v2)

2008-03-20T22:39:41+00:00

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