linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kirill Tkhai <tkhai@yandex.ru>
To: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Kirill Tkhai <ktkhai@parallels.com>
Subject: [PATCH 5/7] sched: Use rq->rd in sched_setaffinity() under RCU read lock
Date: Sat, 20 Sep 2014 20:51:40 +0400	[thread overview]
Message-ID: <20140920165140.16299.45521.stgit@localhost> (raw)
In-Reply-To: <20140920165116.16299.1381.stgit@localhost>

From: Kirill Tkhai <ktkhai@parallels.com>

task_rq(p)->rd and task_rq(p)->rd->span may be used-after-free here.
Probability of NULL pointer derefference isn't zero in this place.

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Cc: <stable@vger.kernel.org> # v3.14+
---
 kernel/sched/core.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 65655a887..a40d6e1 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4015,13 +4015,14 @@ 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_free_new_mask;
 		}
+		rcu_read_unlock();
 	}
 #endif
 again:


  parent reply	other threads:[~2014-09-20 16:51 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-20 16:51 [PATCH 1/7] sched/fair: Remove duplicate code from can_migrate_task() Kirill Tkhai
2014-09-20 16:51 ` [PATCH 2/7] sched: Fix picking a task switching on other cpu (__ARCH_WANT_UNLOCKED_CTXSW) Kirill Tkhai
2014-09-20 18:33   ` Peter Zijlstra
2014-09-20 18:54     ` Peter Zijlstra
2014-09-20 20:09       ` Kirill Tkhai
2014-09-20 20:19         ` Kirill Tkhai
2014-09-20 19:03     ` Peter Zijlstra
2014-09-20 16:51 ` [PATCH 3/7] sched: Use dl_bw_of() under RCU read lock Kirill Tkhai
2014-09-20 18:57   ` Peter Zijlstra
2014-09-20 19:25     ` Kirill Tkhai
2014-09-20 19:32       ` Peter Zijlstra
2014-09-20 16:51 ` [PATCH 4/7] sched: cleanup: Rename out_unlock to out_free_new_mask Kirill Tkhai
2014-09-20 16:51 ` Kirill Tkhai [this message]
2014-09-20 18:59   ` [PATCH 5/7] sched: Use rq->rd in sched_setaffinity() under RCU read lock Peter Zijlstra
2014-09-20 19:05     ` Kirill Tkhai
2014-09-20 19:18       ` Peter Zijlstra
2014-09-20 19:21         ` Kirill Tkhai
2014-09-20 16:51 ` [PATCH 6/7] sched: Delete rq::skip_clock_update == -1 Kirill Tkhai
2014-09-20 19:01   ` Peter Zijlstra
2014-09-21  4:37     ` Mike Galbraith
2014-09-20 16:51 ` [PATCH 7/7] sched/rt: Use resched_curr() in task_tick_rt() Kirill Tkhai

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20140920165140.16299.45521.stgit@localhost \
    --to=tkhai@yandex.ru \
    --cc=ktkhai@parallels.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).