s390/cio: Ensure the copied buf is NUL terminated

[ Upstream commit da7c622cdd ]

Currently, we allocate a lbuf-sized kernel buffer and copy lbuf from
userspace to that buffer. Later, we use scanf on this buffer but we don't
ensure that the string is terminated inside the buffer, this can lead to
OOB read when using scanf. Fix this issue by using memdup_user_nul instead.

Fixes: a4f17cc726 ("s390/cio: add CRW inject functionality")
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-5-f1f1b53a10f4@gmail.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

This commit is contained in:

Bui Quang Minh

2024-04-24 21:44:22 +07:00

committed by

Greg Kroah-Hartman

parent 7db626d273

commit 84b38f4883

1 changed files with 1 additions and 1 deletions

									
										drivers/s390/cio/cio_inject.c
									
		+1
		-1
	
												View File
												
				@@ -95,7 +95,7 @@ static ssize_t crw_inject_write(struct file *file, const char __user *buf,

						return -EINVAL;

					}

					buffer = vmemdup_user(buf, lbuf);

					buffer = memdup_user_nul(buf, lbuf);

					if (IS_ERR(buffer))

						return -ENOMEM;