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From:   Alex Dewar <alex.dewar90@gmail.com>
Cc:     Alex Dewar <alex.dewar90@gmail.com>,
        Doug Ledford <dledford@redhat.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Leon Romanovsky <leon@kernel.org>, linux-rdma@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] RDMA/ucma: Fix resource leak on error path
Date:   Wed,  2 Sep 2020 17:24:51 +0100
Message-Id: <20200902162454.332828-1-alex.dewar90@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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In ucma_process_join(), if the call to xa_alloc() fails, the function
will return without freeing mc. Fix this by jumping to the correct line.

In the process I renamed the jump labels to something more memorable for
extra clarity.

Addresses-Coverity: ("Resource leak")
Fixes: 95fe51096b7a ("RDMA/ucma: Remove mc_list and rely on xarray")
Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
---
 drivers/infiniband/core/ucma.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index f2c9ef6ae481..a5595bd489b0 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1453,7 +1453,7 @@ static ssize_t ucma_process_join(struct ucma_file *file,
 	mc = kzalloc(sizeof(*mc), GFP_KERNEL);
 	if (!mc) {
 		ret = -ENOMEM;
-		goto err1;
+		goto err_put_ctx;
 	}
 
 	mc->ctx = ctx;
@@ -1464,7 +1464,7 @@ static ssize_t ucma_process_join(struct ucma_file *file,
 	if (xa_alloc(&multicast_table, &mc->id, NULL, xa_limit_32b,
 		     GFP_KERNEL)) {
 		ret = -ENOMEM;
-		goto err1;
+		goto err_free_mc;
 	}
 
 	mutex_lock(&ctx->mutex);
@@ -1472,13 +1472,13 @@ static ssize_t ucma_process_join(struct ucma_file *file,
 				  join_state, mc);
 	mutex_unlock(&ctx->mutex);
 	if (ret)
-		goto err2;
+		goto err_xa_erase;
 
 	resp.id = mc->id;
 	if (copy_to_user(u64_to_user_ptr(cmd->response),
 			 &resp, sizeof(resp))) {
 		ret = -EFAULT;
-		goto err3;
+		goto err_leave_multicast;
 	}
 
 	xa_store(&multicast_table, mc->id, mc, 0);
@@ -1486,15 +1486,16 @@ static ssize_t ucma_process_join(struct ucma_file *file,
 	ucma_put_ctx(ctx);
 	return 0;
 
-err3:
+err_leave_multicast:
 	mutex_lock(&ctx->mutex);
 	rdma_leave_multicast(ctx->cm_id, (struct sockaddr *) &mc->addr);
 	mutex_unlock(&ctx->mutex);
 	ucma_cleanup_mc_events(mc);
-err2:
+err_xa_erase:
 	xa_erase(&multicast_table, mc->id);
+err_free_mc:
 	kfree(mc);
-err1:
+err_put_ctx:
 	ucma_put_ctx(ctx);
 	return ret;
 }
-- 
2.28.0