xen/x86/vpmu: Zero struct pt_regs before calling into sample handling code

Boris Ostrovsky · Boris Ostrovsky · commit 70513d58751d · 2018-09-19T11:26:53.000-04:00
Otherwise we may leak kernel stack for events that sample user
registers.

Reported-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Cc: stable@vger.kernel.org
diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c
@@ -478,7 +478,7 @@ static void xen_convert_regs(const struct xen_pmu_regs *xen_regs,
 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();
 

Original file line number	Diff line number	Diff line change
`@@ -478,7 +478,7 @@ static void xen_convert_regs(const struct xen_pmu_regs *xen_regs,`
`478`	`478`	`irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id)`
`479`	`479`	`{`
`480`	`480`	`int err, ret = IRQ_NONE;`
`481`		`- struct pt_regs regs;`
	`481`	`+ struct pt_regs regs = {0};`
`482`	`482`	`const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();`
`483`	`483`	`uint8_t xenpmu_flags = get_xenpmu_flags();`
`484`	`484`