[PATCH 3.16.y-ckt 190/216] audit: don't attempt to lookup PIDs when changing PID filtering audit rules

Luis Henriques
2015-01-12T18:39:22Z

From: Paul Moore <pmoore@redhat.com>

commit 3640dcfa4fd00cd91d88bb86250bdb496f7070c0 upstream.

Commit f1dc4867 ("audit: anchor all pid references in the initial pid
namespace") introduced a find_vpid() call when adding/removing audit
rules with PID/PPID filters; unfortunately this is problematic as
find_vpid() only works if there is a task with the associated PID
alive on the system. The following commands demonstrate a simple
reproducer.

# auditctl -D
# auditctl -l
# autrace /bin/true
# auditctl -l

This patch resolves the problem by simply using the PID provided by
the user without any additional validation, e.g. no calls to check to
see if the task/PID exists.

Cc: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
kernel/auditfilter.c | 13 -------------
1 file changed, 13 deletions(-)

diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 8e9bc9c3dbb7..b2e63ba5f815 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -433,19 +433,6 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
f->val = 0;
}

- if ((f->type == AUDIT_PID) || (f->type == AUDIT_PPID)) {
- struct pid *pid;
- rcu_read_lock();
- pid = find_vpid(f->val);
- if (!pid) {
- rcu_read_unlock();
- err = -ESRCH;
- goto exit_free;
- }
- f->val = pid_nr(pid);
- rcu_read_unlock();
- }
-
err = audit_field_valid(entry, f);
if (err)
goto exit_free;
--
2.1.4