The patch below does not apply to the 3.13-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 465954cd649a7d8cd331695bd24a16bcb5c4c716 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <[email protected]> Date: Sat, 14 Dec 2013 17:33:17 +0100 Subject: [PATCH] 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 <[email protected]> Signed-off-by: Oleg Nesterov <[email protected]> Cc: [email protected] Signed-off-by: Paul Moore <[email protected]> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ded2d47e5ee1..6ace9b3abf0d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5583,11 +5583,11 @@ 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, -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
