Patch "x86/intel_rdt: Fix locking in rdtgroup_schemata_write()" has been added to the 4.10-stable tree

Patch "x86/intel_rdt: Fix locking in rdtgroup_schemata_write()" has been added to the 4.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    x86/intel_rdt: Fix locking in rdtgroup_schemata_write()

to the 4.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     x86-intel_rdt-fix-locking-in-rdtgroup_schemata_write.patch
and it can be found in the queue-4.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 7f00f388712b29005782bad7e4b25942620f3b9c Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@kernel.org>
Date: Tue, 11 Apr 2017 09:14:46 +0200
Subject: x86/intel_rdt: Fix locking in rdtgroup_schemata_write()

From: Jiri Olsa <jolsa@kernel.org>

commit 7f00f388712b29005782bad7e4b25942620f3b9c upstream.

The schemata lock is released before freeing the resource's temporary
tmp_cbms allocation. That's racy versus another write which allocates and
uses new temporary storage, resulting in memory leaks, freeing in use
memory, double a free or any combination of those.

Move the unlock after the release code.

Fixes: 60ec2440c63d ("x86/intel_rdt: Add schemata file")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20170411071446.15241-1-jolsa@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/cpu/intel_rdt_schemata.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/intel_rdt_schemata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_schemata.c
@@ -200,11 +200,11 @@ ssize_t rdtgroup_schemata_write(struct k
 	}
 
 out:
-	rdtgroup_kn_unlock(of->kn);
 	for_each_enabled_rdt_resource(r) {
 		kfree(r->tmp_cbms);
 		r->tmp_cbms = NULL;
 	}
+	rdtgroup_kn_unlock(of->kn);
 	return ret ?: nbytes;
 }
 


Patches currently in stable-queue which might be from jolsa@kernel.org are

queue-4.10/x86-intel_rdt-fix-locking-in-rdtgroup_schemata_write.patch