[Linux-kernel-mentees] [PATCH v2] infiniband: Prevent uninit-value in ucma_accept()

[Peilin Ye]

ucma_accept() is reading uninitialized memory when `in_len` is
less than `offsetof(struct rdma_ucm_accept, ece)`. Fix it.

Reported-and-tested-by: syzbot+086ab5ca9eafd2379aa6@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://syzkaller.appspot.com/bug?id=0bce3bb68cb383fce92f78444e3ef77c764b60ad
Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx>
---
Change in v2:
    - syzbot has reported this bug as "KMSAN: uninit-value in xa_load".
      Add "Reported-and-tested-by:" and "Link:" tags for it.

 drivers/infiniband/core/ucma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index a591fdccdce0..842d297903c0 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1134,7 +1134,7 @@ static ssize_t ucma_listen(struct ucma_file *file, const char __user *inbuf,
 static ssize_t ucma_accept(struct ucma_file *file, const char __user *inbuf,
 			   int in_len, int out_len)
 {
-	struct rdma_ucm_accept cmd;
+	struct rdma_ucm_accept cmd = {};
 	struct rdma_conn_param conn_param;
 	struct rdma_ucm_ece ece = {};
 	struct ucma_context *ctx;
-- 
2.25.1