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From:   Lv Yunlong <lyl2019@mail.ustc.edu.cn>
To:     siglesias@igalia.com, jens.taprogge@taprogge.org,
        gregkh@linuxfoundation.org
Cc:     industrypack-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org, Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Subject: [PATCH] Staging:ipack/carriers/tpci200: Fix a double free in tpci200_pci_probe
Date:   Mon, 26 Apr 2021 08:35:47 -0700
Message-Id: <20210426153547.9058-1-lyl2019@mail.ustc.edu.cn>
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In the out_err_bus_register error branch of tpci200_pci_probe,
tpci200->info->cfg_regs is freed by tpci200_uninstall()->
tpci200_unregister()->pci_iounmap(..,tpci200->info->cfg_regs)
in the first time.

But later, iounmap() is called to free tpci200->info->cfg_regs
again.

My patch sets tpci200->info->cfg_regs to NULL after tpci200_uninstall()
to avoid the double free.

Fixes: cea2f7cdff2af ("Staging: ipack/bridges/tpci200: Use the TPCI200 in big endian mode")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
---
 drivers/ipack/carriers/tpci200.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/ipack/carriers/tpci200.c b/drivers/ipack/carriers/tpci200.c
index ec71063fff76..e1822e87ec3d 100644
--- a/drivers/ipack/carriers/tpci200.c
+++ b/drivers/ipack/carriers/tpci200.c
@@ -596,8 +596,11 @@ static int tpci200_pci_probe(struct pci_dev *pdev,
 
 out_err_bus_register:
 	tpci200_uninstall(tpci200);
+	/* tpci200->info->cfg_regs is unmapped in tpci200_uninstall */
+	tpci200->info->cfg_regs = NULL;
 out_err_install:
-	iounmap(tpci200->info->cfg_regs);
+	if (tpci200->info->cfg_regs)
+		iounmap(tpci200->info->cfg_regs);
 out_err_ioremap:
 	pci_release_region(pdev, TPCI200_CFG_MEM_BAR);
 out_err_pci_request:
-- 
2.25.1