From: Robin Murphy <robin.murphy@arm.com>
Date: Wed, 15 Nov 2017 12:50:06 +0000 (+0000)
Subject: of/pci: Fix theoretical NULL dereference
X-Git-Tag: v4.15-rc1~34^2~8
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c545f637f81ebab88c257a243083a879af0b85b7;p=thirdparty%2Fkernel%2Flinux.git

of/pci: Fix theoretical NULL dereference

In the (relatively mechanical) process of adapting the RID-mapping code
to put the resulting ID in an output argument rather than the funtion
return value, we ended up with the debug print using the argument
pointer rather than the local value, which potentially defeats the
earlier NULL check.

Fixes: 987068fcbdb7: "of/irq: Break out msi-map lookup (again)"
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
---

diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index e9ec931f5b9a5..a7b1cb6c2f657 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -374,7 +374,7 @@ int of_pci_map_rid(struct device_node *np, u32 rid,
 
 		pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
 			np, map_name, map_mask, rid_base, out_base,
-			rid_len, rid, *id_out);
+			rid_len, rid, masked_rid - rid_base + out_base);
 		return 0;
 	}