[PATCH 3.16 160/366] RDMA/ucma: ucma_context reference leak in error path

Ben Hutchings
2018-10-14T23:11:43Z

From: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>

commit ef95a90ae6f4f21990e1f7ced6719784a409e811 upstream.

Validating input parameters should be done before getting the cm_id
otherwise it can leak a cm_id reference.

Fixes: 6a21dfc0d0db ("RDMA/ucma: Limit possible option size")
Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/infiniband/core/ucma.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1204,13 +1204,13 @@ static ssize_t ucma_set_option(struct uc
if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
return -EFAULT;

+ if (unlikely(cmd.optlen > KMALLOC_MAX_SIZE))
+ return -EINVAL;
+
ctx = ucma_get_ctx(file, cmd.id);
if (IS_ERR(ctx))
return PTR_ERR(ctx);

- if (unlikely(cmd.optlen > KMALLOC_MAX_SIZE))
- return -EINVAL;
-
optval = memdup_user((void __user *) (unsigned long) cmd.optval,
cmd.optlen);
if (IS_ERR(optval)) {