When block layer fails to map iov, it calls bio_unmap_user to undo

mapping.  Which is good if pages were mapped - but if they were provided
by someone else and just copied then bad things happen - pages are
released once here, and once by caller, leading to user triggerable BUG
at include/linux/mm.h:246.

Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Petr Vandrovec 2008-11-19 11:12:14 +01:00 committed by Jens Axboe
parent f6f7b52e2f
commit 53cc0b2948

View file

@ -224,7 +224,7 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
*/
bio_get(bio);
bio_endio(bio, 0);
bio_unmap_user(bio);
__blk_rq_unmap_user(bio);
return -EINVAL;
}