linux-kernel - [tip:core/urgent] futex: additional (get|put)_futex

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tip-638f9d766fa5b59953f8d1870f18fbd0cca84d33@git.kernel.org>
Date:	Fri, 13 Mar 2009 00:24:23 GMT
From:	Darren Hart <dvhltc@...ibm.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, dvhltc@...ibm.com, hpa@...or.com,
	mingo@...hat.com, rusty@...tcorp.com.au, peterz@...radead.org,
	tglx@...utronix.de, mingo@...e.hu
Subject: [tip:core/urgent] futex: additional (get|put)_futex_key() fixes

Commit-ID:  638f9d766fa5b59953f8d1870f18fbd0cca84d33
Gitweb:     http://git.kernel.org/tip/638f9d766fa5b59953f8d1870f18fbd0cca84d33
Author:     Darren Hart <dvhltc@...ibm.com>
AuthorDate: Thu, 12 Mar 2009 00:55:46 -0700
Commit:     Ingo Molnar <mingo@...e.hu>
CommitDate: Fri, 13 Mar 2009 01:19:00 +0100

futex: additional (get|put)_futex_key() fixes

Impact: fix races

futex_requeue and futex_lock_pi still had some bad
(get|put)_futex_key() usage. This patch adds the missing
put_futex_keys() and corrects a goto in futex_lock_pi() to avoid
a double get.

Build and boot tested on a 4 way Intel x86_64 workstation.
Passes basic pthread_mutex and PI tests out of
ltp/testcases/realtime.

Signed-off-by: Darren Hart <dvhltc@...ibm.com>
Acked-by: Peter Zijlstra <peterz@...radead.org>
Cc: Rusty Russell <rusty@...tcorp.com.au>
LKML-Reference: <20090312075545.9856.75152.stgit@...n>
Signed-off-by: Ingo Molnar <mingo@...e.hu>


---
 kernel/futex.c |   16 +++++++++++-----
 1 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index 438701a..a66cd2d 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -805,8 +805,10 @@ retry:
 
 		ret = get_user(dummy, uaddr2);
 		if (ret)
-			return ret;
+			goto out_put_keys;
 
+		put_futex_key(fshared, &key2);
+		put_futex_key(fshared, &key1);
 		goto retryfull;
 	}
 
@@ -881,6 +883,9 @@ retry:
 			if (hb1 != hb2)
 				spin_unlock(&hb2->lock);
 
+			put_futex_key(fshared, &key2);
+			put_futex_key(fshared, &key1);
+
 			ret = get_user(curval, uaddr1);
 
 			if (!ret)
@@ -1458,6 +1463,7 @@ retry_locked:
 			 * exit to complete.
 			 */
 			queue_unlock(&q, hb);
+			put_futex_key(fshared, &q.key);
 			cond_resched();
 			goto retry;
 
@@ -1600,13 +1606,12 @@ uaddr_faulted:
 
 	ret = get_user(uval, uaddr);
 	if (!ret)
-		goto retry;
+		goto retry_unlocked;
 
-	if (to)
-		destroy_hrtimer_on_stack(&to->timer);
-	return ret;
+	goto out_put_key;
 }
 
+
 /*
  * Userspace attempted a TID -> 0 atomic transition, and failed.
  * This is the in-kernel slowpath: we look up the PI state (if any),
@@ -1710,6 +1715,7 @@ pi_faulted:
 	}
 
 	ret = get_user(uval, uaddr);
+	put_futex_key(fshared, &key);
 	if (!ret)
 		goto retry;
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/