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| author | David Howells <dhowells@redhat.com> | 2008-11-14 10:39:19 +1100 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2008-11-14 10:39:19 +1100 |
| commit | c69e8d9c01db2adc503464993c358901c9af9de4 (patch) | |
| tree | bed94aaa9aeb7a7834d1c880f72b62a11a752c78 /security/selinux | |
| parent | 86a264abe542cfececb4df129bc45a0338d8cdb9 (diff) | |
| download | linux-c69e8d9c01db2adc503464993c358901c9af9de4.tar.gz linux-c69e8d9c01db2adc503464993c358901c9af9de4.tar.bz2 linux-c69e8d9c01db2adc503464993c358901c9af9de4.zip | |
CRED: Use RCU to access another task's creds and to release a task's own creds
Use RCU to access another task's creds and to release a task's own creds.
This means that it will be possible for the credentials of a task to be
replaced without another task (a) requiring a full lock to read them, and (b)
seeing deallocated memory.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/selinux')
| -rw-r--r-- | security/selinux/selinuxfs.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 10715d1330b9..c86303638235 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -95,13 +95,18 @@ extern void selnl_notify_setenforce(int val); static int task_has_security(struct task_struct *tsk, u32 perms) { - struct task_security_struct *tsec; - - tsec = tsk->cred->security; + const struct task_security_struct *tsec; + u32 sid = 0; + + rcu_read_lock(); + tsec = __task_cred(tsk)->security; + if (tsec) + sid = tsec->sid; + rcu_read_unlock(); if (!tsec) return -EACCES; - return avc_has_perm(tsec->sid, SECINITSID_SECURITY, + return avc_has_perm(sid, SECINITSID_SECURITY, SECCLASS_SECURITY, perms, NULL); } |