3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Oleg Nesterov <o...@redhat.com>
commit c0c1439541f5305b57a83d599af32b74182933fe upstream.
selinux_setprocattr() does ptrace_parent(p) under task_lock(p),
but task_struct->alloc_lock doesn't pin ->parent or ->ptrace,
this looks confusing and triggers the "suspicious RCU usage"
warning because ptrace_parent() does rcu_dereference_check().
And in theory this is wrong, spin_lock()->preempt_disable()
doesn't necessarily imply rcu_read_lock() we need to access
the ->parent.
Reported-by: Evan McNabb <emcn...@redhat.com>
Signed-off-by: Oleg Nesterov <o...@redhat.com>
Signed-off-by: Paul Moore <pmo...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
security/selinux/hooks.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5445,11 +5445,11 @@ static int selinux_setprocattr(struct ta
/* Check for ptracing, and update the task SID if ok.
Otherwise, leave SID unchanged and fail. */
ptsid = 0;
- task_lock(p);
+ rcu_read_lock();
tracer = ptrace_parent(p);
if (tracer)
ptsid = task_sid(tracer);
- task_unlock(p);
+ rcu_read_unlock();
if (tracer) {
error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
