path: root/security
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authorOleg Nesterov <oleg@redhat.com>2013-12-23 17:45:01 -0500
committerPaul Moore <pmoore@redhat.com>2013-12-23 17:45:17 -0500
commitc0c1439541f5305b57a83d599af32b74182933fe (patch)
treee430e1d9e869d9e08a0a7e8677951465568d17dc /security
parent46d01d63221c3508421dd72ff9c879f61053cffc (diff)
selinux: selinux_setprocattr()->ptrace_parent() needs rcu_read_lock()
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 <emcnabb@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
Diffstat (limited to 'security')
1 files changed, 2 insertions, 2 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5db26468b5c3..6625699f497c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5588,11 +5588,11 @@ static int selinux_setprocattr(struct task_struct *p,
/* 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,

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