From: Jan Sokolowski <jan.sokolowski@intel.com>
Date: Fri, 9 Jun 2017 16:00:26 -0700
Subject: IB/hfi1: Handle missing magic values in config file
Patch-mainline: v4.14-rc1
Git-commit: bc5214ee29220251e5507882696ded5ca183b169
References: bsc#1060463 FATE#323043

Driver does not check whether proper configuration file exist in EPROM,
and treats empty partition as possible valid configuration, preventing
fallback to default firmware. Change EPROM read function to treat
missing magic number as read error.

Reviewed-by: Jakub Byczkowski <jakub.byczkowski@intel.com>
Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/hfi1/eprom.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

--- a/drivers/infiniband/hw/hfi1/eprom.c
+++ b/drivers/infiniband/hw/hfi1/eprom.c
@@ -250,7 +250,6 @@ static int read_partition_platform_confi
 {
 	void *buffer;
 	void *p;
-	u32 length;
 	int ret;
 
 	buffer = kmalloc(P1_SIZE, GFP_KERNEL);
@@ -265,13 +264,13 @@ static int read_partition_platform_confi
 
 	/* scan for image magic that may trail the actual data */
 	p = strnstr(buffer, IMAGE_TRAIL_MAGIC, P1_SIZE);
-	if (p)
-		length = p - buffer;
-	else
-		length = P1_SIZE;
+	if (!p) {
+		kfree(buffer);
+		return -ENOENT;
+	}
 
 	*data = buffer;
-	*size = length;
+	*size = p - buffer;
 	return 0;
 }