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[3.16.y-ckt,stable] Patch "sched: Use rq->rd in sched_setaffinity() under RCU read lock" has been added to staging queue

Message ID 1416223070-25484-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Nov. 17, 2014, 11:17 a.m. UTC 
This is a note to let you know that I have just added a patch titled

    sched: Use rq->rd in sched_setaffinity() under RCU read lock

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 5ed505f6af2faa9f6cafd8b428b86361e2f3b93a Mon Sep 17 00:00:00 2001
From: Kirill Tkhai <ktkhai@parallels.com>
Date: Mon, 22 Sep 2014 22:36:36 +0400
Subject: sched: Use rq->rd in sched_setaffinity() under RCU read lock

commit f1e3a0932f3a9554371792a7daaf1e0eb19f66d5 upstream.

Probability of use-after-free isn't zero in this place.

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140922183636.11015.83611.stgit@localhost
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[ luis: backported to 3.16: used peterz's backport to 3.17 ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 kernel/sched/core.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--
2.1.0
diff mbox

Patch

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 169720f46c30..07f41f4fe4db 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3983,13 +3983,14 @@  long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
 	 * root_domain.
 	 */
 #ifdef CONFIG_SMP
-	if (task_has_dl_policy(p)) {
-		const struct cpumask *span = task_rq(p)->rd->span;
-
-		if (dl_bandwidth_enabled() && !cpumask_subset(span, new_mask)) {
+	if (task_has_dl_policy(p) && dl_bandwidth_enabled()) {
+		rcu_read_lock();
+		if (!cpumask_subset(task_rq(p)->rd->span, new_mask)) {
 			retval = -EBUSY;
+			rcu_read_unlock();
 			goto out_unlock;
 		}
+		rcu_read_unlock();
 	}
 #endif
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