[PATCH] io_uring: Initialize variable before use

Muhammad Usama Anjum
2021-03-22T18:42:55Z

1) Initialize the struct msghdr msg in the start of the function
2) Uninitialized variable msg.msg_flags can get used if branch happens to
out_free before initialization.

So initialize variable in question in the start of the function for
simplicity in logic and use.

Addresses-Coverity: ("Uninitialized variable")
Addresses-Coverity: ("Uninitialized variable read")
Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
---
fs/io_uring.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index bba74631954b..d5f83326abff 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4677,7 +4677,8 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_buffer *kbuf;
struct io_sr_msg *sr = &req->sr_msg;
- struct msghdr msg;
+ struct msghdr msg = {.msg_name = NULL, .msg_control = NULL, .msg_controllen = 0,
+ .msg_namelen = 0, .msg_iocb = NULL, .msg_flags = 0};
void __user *buf = sr->buf;
struct socket *sock;
struct iovec iov;
@@ -4701,13 +4702,6 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
if (unlikely(ret))
goto out_free;

- msg.msg_name = NULL;
- msg.msg_control = NULL;
- msg.msg_controllen = 0;
- msg.msg_namelen = 0;
- msg.msg_iocb = NULL;
- msg.msg_flags = 0;
-
flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
if (flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
--
2.25.1