floppy: fix use-after-free in module load failure path
Commit 488211844e0c ("floppy: switch to one queue per drive instead of
sharing a queue") introduced a use-after-free. We do "put_disk()" on
the disk device _before_ we then clean up the queue associated with that
disk.
Move the put_disk() down to avoid dereferencing a free'd data structure.
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Reported-and-tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 767107c..8f19b38 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4363,9 +4363,9 @@
out_put_disk:
while (dr--) {
del_timer(&motor_off_timer[dr]);
- put_disk(disks[dr]);
if (disks[dr]->queue)
blk_cleanup_queue(disks[dr]->queue);
+ put_disk(disks[dr]);
}
return err;
}