[PATCH 4.19 139/346] staging: gasket: interrupt: fix the missed eventfd_ctx_put() in gasket_interrupt.c

[Greg Kroah-Hartman]

From: Jing Xiangfeng <jingxiangfeng@xxxxxxxxxx>

[ Upstream commit ab5b769a23af12a675b9f3d7dd529250c527f5ac ]

gasket_interrupt_set_eventfd() misses to call eventfd_ctx_put() in an
error path. We check interrupt is valid before calling
eventfd_ctx_fdget() to fix it.

There is the same issue in gasket_interrupt_clear_eventfd(), Add the
missed function call to fix it.

Fixes: 9a69f5087ccc ("drivers/staging: Gasket driver framework + Apex driver")
Signed-off-by: Jing Xiangfeng <jingxiangfeng@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20201112064924.99680-1-jingxiangfeng@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/staging/gasket/gasket_interrupt.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/gasket/gasket_interrupt.c b/drivers/staging/gasket/gasket_interrupt.c
index 1cfbc120f2284..225460c535d61 100644
--- a/drivers/staging/gasket/gasket_interrupt.c
+++ b/drivers/staging/gasket/gasket_interrupt.c
@@ -527,14 +527,16 @@ int gasket_interrupt_system_status(struct gasket_dev *gasket_dev)
 int gasket_interrupt_set_eventfd(struct gasket_interrupt_data *interrupt_data,
 				 int interrupt, int event_fd)
 {
-	struct eventfd_ctx *ctx = eventfd_ctx_fdget(event_fd);
-
-	if (IS_ERR(ctx))
-		return PTR_ERR(ctx);
+	struct eventfd_ctx *ctx;
 
 	if (interrupt < 0 || interrupt >= interrupt_data->num_interrupts)
 		return -EINVAL;
 
+	ctx = eventfd_ctx_fdget(event_fd);
+
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
 	interrupt_data->eventfd_ctxs[interrupt] = ctx;
 	return 0;
 }
@@ -545,6 +547,9 @@ int gasket_interrupt_clear_eventfd(struct gasket_interrupt_data *interrupt_data,
 	if (interrupt < 0 || interrupt >= interrupt_data->num_interrupts)
 		return -EINVAL;
 
-	interrupt_data->eventfd_ctxs[interrupt] = NULL;
+	if (interrupt_data->eventfd_ctxs[interrupt]) {
+		eventfd_ctx_put(interrupt_data->eventfd_ctxs[interrupt]);
+		interrupt_data->eventfd_ctxs[interrupt] = NULL;
+	}
 	return 0;
 }
-- 
2.27.0