floppy: fix another use-after-free

d017bf6b · Vivek Goyal <[email protected]> · 2010-11-06 08:16:05 -04:00

While scanning the floopy code due to c093ee4f07f4 ("floppy: fix
use-after-free in module load failure path"), I found one more instance
of trying to access disk->queue pointer after doing put_disk() on
gendisk.  For some reason , floppy moule still loads/unloads fine.  The
object is probably still around with right pointer values.

 o There seems to be one more instance of trying to cleanup the request
   queue after we have called put_disk() on associated gendisk.

 o This fix is more out of code inspection.  Even without this fix for
   some reason I am able to load/unload floppy module without any
   issues.

 o Floppy module loads/unloads fine after the fix.

Signed-off-by: Vivek Goyal <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: d017bf6b4ff57db16a481a48bdad79274610a403
Parents: 151f52f0

Changes

1 files changed · +1 −1

File	Status	Add	Del	Content
drivers/block/floppy.c	modified	+1	−1	View file

drivers/block/floppy.c

View file

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 8f19b38..3951020 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4573,8 +4573,8 @@ static void __exit floppy_module_exit(void)
 			device_remove_file(&floppy_device[drive].dev, &dev_attr_cmos);
 			platform_device_unregister(&floppy_device[drive]);
 		}
-		put_disk(disks[drive]);
 		blk_cleanup_queue(disks[drive]->queue);
+		put_disk(disks[drive]);
 	}
 
 	del_timer_sync(&fd_timeout);