[PATCH] drivers: misc: ti-st: fix potential race if st_kim_start fails

[Oleksandr Kozaruk]

If st_kim_start() fails registered protocols should be removed. This is
done by calling st_reg_complete(), which as comment states is called
with spin lock held. But in st_register() when st_kim_start fails it
is called without holding spin lock, creating possibility of concurrent
access to st_gdata data members.
Hold spin lock while calling st_reg_complete if st_kim_start() fails.

Signed-off-by: Oleksandr Kozaruk <oleksandr.kozaruk@xxxxxxxxxxxxxxx>
---
 drivers/misc/ti-st/st_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index 0a14280..8d64b68 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -562,7 +562,9 @@ long st_register(struct st_proto_s *new_proto)
 			if ((st_gdata->protos_registered != ST_EMPTY) &&
 			    (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 				pr_err(" KIM failure complete callback ");
+				spin_lock_irqsave(&st_gdata->lock, flags);
 				st_reg_complete(st_gdata, err);
+				spin_unlock_irqrestore(&st_gdata->lock, flags);
 				clear_bit(ST_REG_PENDING, &st_gdata->st_state);
 			}
 			return -EINVAL;
-- 
1.8.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/