From: Roland Dreier <roland@purestorage.com>
Date: Tue, 3 Apr 2018 22:33:01 +0000 (-0700)
Subject: RDMA/ucma: Don't allow setting RDMA_OPTION_IB_PATH without an RDMA device
X-Git-Tag: v4.17-rc1~94^2~34
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=8435168d50e66fa5eae01852769d20a36f9e5e83;p=linux.git

RDMA/ucma: Don't allow setting RDMA_OPTION_IB_PATH without an RDMA device

Check to make sure that ctx->cm_id->device is set before we use it.
Otherwise userspace can trigger a NULL dereference by doing
RDMA_USER_CM_CMD_SET_OPTION on an ID that is not bound to a device.

Cc: <stable@vger.kernel.org>
Reported-by: <syzbot+a67bc93e14682d92fc2f@syzkaller.appspotmail.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---

diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 2abb70c26559..5e4f2cce7383 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1231,6 +1231,9 @@ static int ucma_set_ib_path(struct ucma_context *ctx,
 	if (!optlen)
 		return -EINVAL;
 
+	if (!ctx->cm_id->device)
+		return -EINVAL;
+
 	memset(&sa_path, 0, sizeof(sa_path));
 
 	sa_path.rec_type = SA_PATH_REC_TYPE_IB;