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Drivers: hv: vmbus: Fix synic per-cpu context initialization 

If hv_synic_alloc() errors out, the state of the per-cpu context
for some CPUs is unknown since the zero'ing is done as each
CPU is iterated over.  In such case, hv_synic_cleanup() may try to
free memory based on uninitialized values.  Fix this by zero'ing
the per-cpu context for all CPUs before doing any memory
allocations that might fail.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Michael Kelley 2018-08-10 23:06:11 +00:00 committed by Greg Kroah-Hartman
parent 8e6925631a
commit f25a7ece08
1 changed files with 12 additions and 3 deletions
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15
drivers/hv/hv.c
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@ -189,6 +189,17 @@ static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
int hv_synic_alloc(void)
{
int cpu;
struct hv_per_cpu_context *hv_cpu;
/*
* First, zero all per-cpu memory areas so hv_synic_free() can
* detect what memory has been allocated and cleanup properly
* after any failures.
*/
for_each_present_cpu(cpu) {
hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
memset(hv_cpu, 0, sizeof(*hv_cpu));
}
hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask),
GFP_KERNEL);
@ -198,10 +209,8 @@ int hv_synic_alloc(void)
}
for_each_present_cpu(cpu) {
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
memset(hv_cpu, 0, sizeof(*hv_cpu));
tasklet_init(&hv_cpu->msg_dpc,
vmbus_on_msg_dpc, (unsigned long) hv_cpu);