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| author | Oleg Nesterov <oleg@redhat.com> | 2013-12-23 17:45:01 -0500 |
|---|---|---|
| committer | Paul Moore <pmoore@redhat.com> | 2013-12-23 17:45:17 -0500 |
| commit | c0c1439541f5305b57a83d599af32b74182933fe (patch) | |
| tree | e430e1d9e869d9e08a0a7e8677951465568d17dc | |
| parent | 46d01d63221c3508421dd72ff9c879f61053cffc (diff) | |
| download | linux-c0c1439541f5305b57a83d599af32b74182933fe.tar.gz linux-c0c1439541f5305b57a83d599af32b74182933fe.tar.bz2 linux-c0c1439541f5305b57a83d599af32b74182933fe.zip | |
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>
| -rw-r--r-- | security/selinux/hooks.c | 4 |
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, |