From 84b38f48836662c4bfae646c014f4e981e16a2b2 Mon Sep 17 00:00:00 2001 From: Bui Quang Minh Date: Wed, 24 Apr 2024 21:44:22 +0700 Subject: [PATCH] s390/cio: Ensure the copied buf is NUL terminated [ Upstream commit da7c622cddd4fe36be69ca61e8c42e43cde94784 ] 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: a4f17cc72671 ("s390/cio: add CRW inject functionality") Signed-off-by: Bui Quang Minh Reviewed-by: Heiko Carstens Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-5-f1f1b53a10f4@gmail.com Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin --- drivers/s390/cio/cio_inject.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/s390/cio/cio_inject.c b/drivers/s390/cio/cio_inject.c index 8613fa937237..a2e771ebae8e 100644 --- a/drivers/s390/cio/cio_inject.c +++ b/drivers/s390/cio/cio_inject.c @@ -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;