From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Michael Kelley <mikelley@microsoft.com>,
Dan Carpenter <dan.carpenter@oracle.com>,
"K . Y . Srinivasan" <kys@microsoft.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>,
linux-hyperv@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 077/103] Drivers: hv: vmbus: Fix synic per-cpu context initialization
Date: Fri, 8 Nov 2019 06:42:42 -0500 [thread overview]
Message-ID: <20191108114310.14363-77-sashal@kernel.org> (raw)
In-Reply-To: <20191108114310.14363-1-sashal@kernel.org>
From: Michael Kelley <mikelley@microsoft.com>
[ Upstream commit f25a7ece08bdb1f2b3c4bbeae942682fc3a99dde ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hv/hv.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index fe041f22521da..23f312b4c6aa2 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -148,6 +148,17 @@ 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 = kzalloc(sizeof(struct cpumask) * nr_node_ids,
GFP_ATOMIC);
@@ -157,10 +168,8 @@ 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);
--
2.20.1
parent reply other threads:[~2019-11-08 11:57 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20191108114310.14363-1-sashal@kernel.org>]
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