[PATCH 6.1 0171/1146] x86/xen: Fix memory leak in xen_init_lock_cpu()

Greg Kroah-Hartman
2022-12-28T15:20:23Z

From: Xiu Jianfeng <xiujianfeng@huawei.com>

[ Upstream commit ca84ce153d887b1dc8b118029976cc9faf2a9b40 ]

In xen_init_lock_cpu(), the @name has allocated new string by kasprintf(),
if bind_ipi_to_irqhandler() fails, it should be freed, otherwise may lead
to a memory leak issue, fix it.

Fixes: 2d9e1e2f58b5 ("xen: implement Xen-specific spinlocks")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221123155858.11382-3-xiujianfeng@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/xen/spinlock.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 043c73dfd2c9..5c6fc16e4b92 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -75,6 +75,7 @@ void xen_init_lock_cpu(int cpu)
cpu, per_cpu(lock_kicker_irq, cpu));

name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
+ per_cpu(irq_name, cpu) = name;
irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
cpu,
dummy_handler,
@@ -85,7 +86,6 @@ void xen_init_lock_cpu(int cpu)
if (irq >= 0) {
disable_irq(irq); /* make sure it's never delivered */
per_cpu(lock_kicker_irq, cpu) = irq;
- per_cpu(irq_name, cpu) = name;
}

printk("cpu %d spinlock event irq %d\n", cpu, irq);
@@ -98,6 +98,8 @@ void xen_uninit_lock_cpu(int cpu)
if (!xen_pvspin)
return;

+ kfree(per_cpu(irq_name, cpu));
+ per_cpu(irq_name, cpu) = NULL;
/*
* When booting the kernel with 'mitigations=auto,nosmt', the secondary
* CPUs are not activated, and lock_kicker_irq is not initialized.
@@ -108,8 +110,6 @@ void xen_uninit_lock_cpu(int cpu)

unbind_from_irqhandler(irq, NULL);
per_cpu(lock_kicker_irq, cpu) = -1;
- kfree(per_cpu(irq_name, cpu));
- per_cpu(irq_name, cpu) = NULL;
}

PV_CALLEE_SAVE_REGS_THUNK(xen_vcpu_stolen);
--
2.35.1