linux-kernel - [PATCH 3.13.y-ckt 09/30] x86/irq: Call chip->irq_set

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: <1455140528-17076-10-git-send-email-kamal@canonical.com>
Date:	Wed, 10 Feb 2016 13:41:47 -0800
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	Jiang Liu <jiang.liu@...ux.intel.com>,
	Jeremiah Mahler <jmmahler@...il.com>,
	andy.shevchenko@...il.com, Guenter Roeck <linux@...ck-us.net>,
	Joe Lawrence <joe.lawrence@...atus.com>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.13.y-ckt 09/30] x86/irq: Call chip->irq_set_affinity in proper context

3.13.11-ckt35 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Thomas Gleixner <tglx@...utronix.de>

commit e23b257c293ce4bcc8cabb2aa3097b6ed8a8261a upstream.

setup_ioapic_dest() calls irqchip->irq_set_affinity() completely
unprotected. That's wrong in several aspects:

 - it opens a race window where irq_set_affinity() can be interrupted and the
   irq chip left in unconsistent state.

 - it triggers a lockdep splat when we fix the vector race for 4.3+ because
   vector lock is taken with interrupts enabled.

The proper calling convention is irq descriptor lock held and interrupts
disabled.

Reported-and-tested-by: Borislav Petkov <bp@...en8.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Jiang Liu <jiang.liu@...ux.intel.com>
Cc: Jeremiah Mahler <jmmahler@...il.com>
Cc: andy.shevchenko@...il.com
Cc: Guenter Roeck <linux@...ck-us.net>
Cc: Joe Lawrence <joe.lawrence@...atus.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1601140919420.3575@nanos
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
[ kamal: backport to 3.19-stable: context ]
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 arch/x86/kernel/apic/io_apic.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e63a5bd..94a3320 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3610,6 +3610,7 @@ void __init setup_ioapic_dest(void)
 {
 	int pin, ioapic, irq, irq_entry;
 	const struct cpumask *mask;
+	struct irq_desc *desc;
 	struct irq_data *idata;
 
 	if (skip_ioapic_setup == 1)
@@ -3625,7 +3626,9 @@ void __init setup_ioapic_dest(void)
 		if ((ioapic > 0) && (irq > 16))
 			continue;
 
-		idata = irq_get_irq_data(irq);
+		desc = irq_to_desc(irq);
+		raw_spin_lock_irq(&desc->lock);
+		idata = irq_desc_get_irq_data(desc);
 
 		/*
 		 * Honour affinities which have been set in early boot
@@ -3636,6 +3639,7 @@ void __init setup_ioapic_dest(void)
 			mask = apic->target_cpus();
 
 		x86_io_apic_ops.set_affinity(idata, mask, false);
+		raw_spin_unlock_irq(&desc->lock);
 	}
 
 }
-- 
1.9.1