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From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Rob Herring <robh@kernel.org>,
	Marek Vasut <marek.vasut+renesas@gmail.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type()
Date: Tue,  4 Aug 2020 14:04:30 +0200	[thread overview]
Message-ID: <20200804120430.9253-1-geert+renesas@glider.be> (raw)

The conversion to modern host bridge probing made the driver allocate
its private data using devm_pci_alloc_host_bridge(), but forgot to
remove the old allocation.  Hence part of the driver initialization is
done using the new instance, while another part is done using the old
instance, leading to a crash due to uninitialized bridge DMA ranges:

    Unable to handle kernel NULL pointer dereference at virtual address 00000008
    pgd = (ptrval)
    [00000008] *pgd=00000000
    Internal error: Oops: 5 [#1] SMP ARM
    CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1-shmobile-00035-g92d69cc6275845a7 #645
    Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
    PC is at rcar_pci_probe+0x154/0x340
    LR is at _raw_spin_unlock_irqrestore+0x18/0x20

Fix this by dropping the old allocation.

Fixes: 92d69cc6275845a7 ("PCI: rcar-gen2: Convert to use modern host bridge probe functions")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/pci/controller/pci-rcar-gen2.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/pci/controller/pci-rcar-gen2.c b/drivers/pci/controller/pci-rcar-gen2.c
index 046965d284a6d54e..c9530038ca9a53fc 100644
--- a/drivers/pci/controller/pci-rcar-gen2.c
+++ b/drivers/pci/controller/pci-rcar-gen2.c
@@ -302,10 +302,6 @@ static int rcar_pci_probe(struct platform_device *pdev)
 	if (mem_res->start & 0xFFFF)
 		return -EINVAL;
 
-	priv = devm_kzalloc(dev, sizeof(struct rcar_pci_priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
-
 	priv->mem_res = *mem_res;
 	priv->cfg_res = cfg_res;
 
-- 
2.17.1


             reply	other threads:[~2020-08-04 12:30 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-04 12:04 Geert Uytterhoeven [this message]
2020-08-04 15:13 ` [PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type() Rob Herring
2020-08-04 16:13 ` Lorenzo Pieralisi
2020-08-04 16:22   ` Bjorn Helgaas
2020-08-04 16:48     ` Rob Herring

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