[PATCH 5.15 12/72] RDMA/uverbs: Check for null return of kmalloc_array

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Jiasheng Jiang <jiasheng@iscas.ac.cn>

commit 7694a7de22c53a312ea98960fcafc6ec62046531 upstream.

Because of the possible failure of the allocation, data might be NULL
pointer and will cause the dereference of the NULL pointer later.
Therefore, it might be better to check it and return -ENOMEM.

Fixes: 6884c6c4bd09 ("RDMA/verbs: Store the write/write_ex uapi entry points in the uverbs_api")
Link: https://lore.kernel.org/r/20211231093315.1917667-1-jiasheng@iscas.ac.cn
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/infiniband/core/uverbs_uapi.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/infiniband/core/uverbs_uapi.c
+++ b/drivers/infiniband/core/uverbs_uapi.c
@@ -447,6 +447,9 @@ static int uapi_finalize(struct uverbs_a
 	uapi->num_write_ex = max_write_ex + 1;
 	data = kmalloc_array(uapi->num_write + uapi->num_write_ex,
 			     sizeof(*uapi->write_methods), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
 	for (i = 0; i != uapi->num_write + uapi->num_write_ex; i++)
 		data[i] = &uapi->notsupp_method;
 	uapi->write_methods = data;