Patch "x86/apic/vector: Fix off by one in error path" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

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

    x86/apic/vector: Fix off by one in error path

to the 4.9-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-apic-vector-fix-off-by-one-in-error-path.patch
and it can be found in the queue-4.9 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 45d55e7bac4028af93f5fa324e69958a0b868e96 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 16 Jan 2018 12:20:18 +0100
Subject: x86/apic/vector: Fix off by one in error path

From: Thomas Gleixner <tglx@linutronix.de>

commit 45d55e7bac4028af93f5fa324e69958a0b868e96 upstream.

Keith reported the following warning:

WARNING: CPU: 28 PID: 1420 at kernel/irq/matrix.c:222 irq_matrix_remove_managed+0x10f/0x120
  x86_vector_free_irqs+0xa1/0x180
  x86_vector_alloc_irqs+0x1e4/0x3a0
  msi_domain_alloc+0x62/0x130

The reason for this is that if the vector allocation fails the error
handling code tries to free the failed vector as well, which causes the
above imbalance warning to trigger.

Adjust the error path to handle this correctly.

Fixes: b5dc8e6c21e7 ("x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors")
Reported-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Keith Busch <keith.busch@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801161217300.1823@nanos
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/apic/vector.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -361,14 +361,17 @@ static int x86_vector_alloc_irqs(struct
 		irq_data->chip_data = data;
 		irq_data->hwirq = virq + i;
 		err = assign_irq_vector_policy(virq + i, node, data, info);
-		if (err)
+		if (err) {
+			irq_data->chip_data = NULL;
+			free_apic_chip_data(data);
 			goto error;
+		}
 	}
 
 	return 0;
 
 error:
-	x86_vector_free_irqs(domain, virq, i + 1);
+	x86_vector_free_irqs(domain, virq, i);
 	return err;
 }
 


Patches currently in stable-queue which might be from tglx@linutronix.de are

queue-4.9/futex-prevent-overflow-by-strengthen-input-validation.patch
queue-4.9/timers-unconditionally-check-deferrable-base.patch
queue-4.9/x86-apic-vector-fix-off-by-one-in-error-path.patch
queue-4.9/objtool-improve-error-message-for-bad-file-argument.patch
queue-4.9/x86-mm-pkeys-fix-fill_sig_info_pkey.patch
queue-4.9/x86-tsc-fix-erroneous-tsc-rate-on-skylake-xeon.patch
queue-4.9/sched-deadline-zero-out-positive-runtime-after-throttling-constrained-tasks.patch
queue-4.9/module-add-retpoline-tag-to-vermagic.patch
queue-4.9/x86-retpoline-fill-rsb-on-context-switch-for-affected-cpus.patch
queue-4.9/x86-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.patch
queue-4.9/x86-cpufeature-move-processor-tracing-out-of-scattered-features.patch