| Message ID | 1389636640-9948-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 0963169..6b0b250 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5455,11 +5455,11 @@ 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,
This is a note to let you know that I have just added a patch titled selinux: selinux_setprocattr()->ptrace_parent() needs rcu_read_lock() to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.16. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From fbf8f2e40913388766f54f2b024cb4cb2ea8a4d6 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg@redhat.com> Date: Mon, 23 Dec 2013 17:45:01 -0500 Subject: selinux: selinux_setprocattr()->ptrace_parent() needs rcu_read_lock() 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 <emcnabb@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- security/selinux/hooks.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 1.8.3.2