From: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Date: Fri, 31 Dec 2021 17:33:15 +0800
Subject: RDMA/uverbs: Check for null return of kmalloc_array
Patch-mainline: v5.16
Git-commit: 7694a7de22c53a312ea98960fcafc6ec62046531
References: jsc#SLE-19249 bsc#1206398 CVE-2022-3105

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 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;