[PATCH 4.18 45/88] xen/x86/vpmu: Zero struct pt_regs before calling into sample handling code

[Greg Kroah-Hartman]

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

------------------

From: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>

commit 70513d58751d7c6c1a0133557b13089b9f2e3e66 upstream.

Otherwise we may leak kernel stack for events that sample user
registers.

Reported-by: Mark Rutland <mark.rutland@xxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/xen/pmu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/xen/pmu.c
+++ b/arch/x86/xen/pmu.c
@@ -478,7 +478,7 @@ static void xen_convert_regs(const struc
 irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id)
 {
 	int err, ret = IRQ_NONE;
-	struct pt_regs regs;
+	struct pt_regs regs = {0};
 	const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
 	uint8_t xenpmu_flags = get_xenpmu_flags();