diff options
author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2015-01-05 15:27:51 (GMT) |
---|---|---|
committer | David Vrabel <david.vrabel@citrix.com> | 2015-01-08 13:55:25 (GMT) |
commit | 7be0772d19103b3eac3c2e9ac325df2563273fdc (patch) | |
tree | 649728c76fed0d5e0a9766971d9f3376f8eea785 /arch/x86 | |
parent | a97dae1a2e92e728d28515e88e8eda151f5796f5 (diff) | |
download | linux-7be0772d19103b3eac3c2e9ac325df2563273fdc.tar.xz |
x86/xen: avoid freeing static 'name' when kasprintf() fails
In case kasprintf() fails in xen_setup_timer() we assign name to the
static string "<timer kasprintf failed>". We, however, don't check
that fact before issuing kfree() in xen_teardown_timer(), kernel is
supposed to crash with 'kernel BUG at mm/slub.c:3341!'
Solve the issue by making name a fixed length string inside struct
xen_clock_event_device. 16 bytes should be enough.
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/xen/time.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 23019b4..6908734 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -391,7 +391,7 @@ static const struct clock_event_device *xen_clockevent = struct xen_clock_event_device { struct clock_event_device evt; - char *name; + char name[16]; }; static DEFINE_PER_CPU(struct xen_clock_event_device, xen_clock_events) = { .evt.irq = -1 }; @@ -420,39 +420,33 @@ void xen_teardown_timer(int cpu) if (evt->irq >= 0) { unbind_from_irqhandler(evt->irq, NULL); evt->irq = -1; - kfree(per_cpu(xen_clock_events, cpu).name); - per_cpu(xen_clock_events, cpu).name = NULL; } } void xen_setup_timer(int cpu) { - char *name; - struct clock_event_device *evt; + struct xen_clock_event_device *xevt = &per_cpu(xen_clock_events, cpu); + struct clock_event_device *evt = &xevt->evt; int irq; - evt = &per_cpu(xen_clock_events, cpu).evt; WARN(evt->irq >= 0, "IRQ%d for CPU%d is already allocated\n", evt->irq, cpu); if (evt->irq >= 0) xen_teardown_timer(cpu); printk(KERN_INFO "installing Xen timer for CPU %d\n", cpu); - name = kasprintf(GFP_KERNEL, "timer%d", cpu); - if (!name) - name = "<timer kasprintf failed>"; + snprintf(xevt->name, sizeof(xevt->name), "timer%d", cpu); irq = bind_virq_to_irqhandler(VIRQ_TIMER, cpu, xen_timer_interrupt, IRQF_PERCPU|IRQF_NOBALANCING|IRQF_TIMER| IRQF_FORCE_RESUME|IRQF_EARLY_RESUME, - name, NULL); + xevt->name, NULL); (void)xen_set_irq_priority(irq, XEN_IRQ_PRIORITY_MAX); memcpy(evt, xen_clockevent, sizeof(*evt)); evt->cpumask = cpumask_of(cpu); evt->irq = irq; - per_cpu(xen_clock_events, cpu).name = name; } |