fpga: do not access region struct after fpga_region_unregister

atull-altera · gregkh · commit 34bd283396af · 2018-09-30T08:49:55.000-07:00
A couple drivers were accessing the region struct after it had been
freed.  Save off the pointer to the mgr before the region struct gets
freed.

Signed-off-by: Alan Tull &lt;atull@kernel.org&gt;
Acked-by: Moritz Fischer &lt;mdf@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
@@ -14,6 +14,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/fpga/fpga-mgr.h>
 #include <linux/fpga/fpga-region.h>
 
 #include "dfl-fme-pr.h"
@@ -66,9 +67,10 @@ static int fme_region_probe(struct platform_device *pdev)
 static int fme_region_remove(struct platform_device *pdev)
 {
 	struct fpga_region *region = dev_get_drvdata(&pdev->dev);
+	struct fpga_manager *mgr = region->mgr;
 
 	fpga_region_unregister(region);
-	fpga_mgr_put(region->mgr);
+	fpga_mgr_put(mgr);
 
 	return 0;
 }
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
@@ -437,9 +437,10 @@ static int of_fpga_region_probe(struct platform_device *pdev)
 static int of_fpga_region_remove(struct platform_device *pdev)
 {
 	struct fpga_region *region = platform_get_drvdata(pdev);
+	struct fpga_manager *mgr = region->mgr;
 
 	fpga_region_unregister(region);
-	fpga_mgr_put(region->mgr);
+	fpga_mgr_put(mgr);
 
 	return 0;
 }

Original file line number	Diff line number	Diff line change
`@@ -437,9 +437,10 @@ static int of_fpga_region_probe(struct platform_device *pdev)`
`437`	`437`	`static int of_fpga_region_remove(struct platform_device *pdev)`
`438`	`438`	`{`
`439`	`439`	`struct fpga_region *region = platform_get_drvdata(pdev);`
	`440`	`+ struct fpga_manager *mgr = region->mgr;`
`440`	`441`
`441`	`442`	`fpga_region_unregister(region);`
`442`		`- fpga_mgr_put(region->mgr);`
	`443`	`+ fpga_mgr_put(mgr);`
`443`	`444`
`444`	`445`	`return 0;`
`445`	`446`	`}`