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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Lv Yunlong <lyl2019@mail.ustc.edu.cn>,
        Leon Romanovsky <leonro@nvidia.com>,
        Devesh Sharma <devesh.sharma@broadcom.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 656/677] RDMA/bnxt_re: Fix a double free in bnxt_qplib_alloc_res
Date:   Wed, 12 May 2021 16:51:42 +0200
Message-Id: <20210512144859.160826630@linuxfoundation.org>
In-Reply-To: <20210512144837.204217980@linuxfoundation.org>
References: <20210512144837.204217980@linuxfoundation.org>
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From: Lv Yunlong <lyl2019@mail.ustc.edu.cn>

[ Upstream commit 34b39efa5ae82fc0ad0acc27653c12a56328dbbe ]

In bnxt_qplib_alloc_res, it calls bnxt_qplib_alloc_dpi_tbl().  Inside
bnxt_qplib_alloc_dpi_tbl, dpit->dbr_bar_reg_iomem is freed via
pci_iounmap() in unmap_io error branch. After the callee returns err code,
bnxt_qplib_alloc_res calls
bnxt_qplib_free_res()->bnxt_qplib_free_dpi_tbl() in the fail branch. Then
dpit->dbr_bar_reg_iomem is freed in the second time by pci_iounmap().

My patch set dpit->dbr_bar_reg_iomem to NULL after it is freed by
pci_iounmap() in the first time, to avoid the double free.

Fixes: 1ac5a4047975 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Link: https://lore.kernel.org/r/20210426140614.6722-1-lyl2019@mail.ustc.edu.cn
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/hw/bnxt_re/qplib_res.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/infiniband/hw/bnxt_re/qplib_res.c b/drivers/infiniband/hw/bnxt_re/qplib_res.c
index fa7878336100..3ca47004b752 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_res.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_res.c
@@ -854,6 +854,7 @@ static int bnxt_qplib_alloc_dpi_tbl(struct bnxt_qplib_res     *res,
 
 unmap_io:
 	pci_iounmap(res->pdev, dpit->dbr_bar_reg_iomem);
+	dpit->dbr_bar_reg_iomem = NULL;
 	return -ENOMEM;
 }
 
-- 
2.30.2