From 1cd96c242a829d52f7a5ae98f554ca9775429685 Mon Sep 17 00:00:00 2001 From: Boaz Harrosh Date: Tue, 24 Mar 2009 12:35:07 +0100 Subject: [PATCH] block: WARN in __blk_put_request() for potential bio leak Put a WARN_ON in __blk_put_request if it is about to leak bio(s). This is a serious bug that can happen in error handling code paths. For this to work I have fixed a couple of places in block/ where request->bio != NULL ownership was not honored. And a small cleanup at sg_io() while at it. Signed-off-by: Boaz Harrosh Signed-off-by: Jens Axboe --- block/blk-core.c | 3 +++ block/blk-merge.c | 2 ++ block/scsi_ioctl.c | 21 ++++----------------- 3 files changed, 9 insertions(+), 17 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 7b63c9b6333d..996ed906d8ca 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1062,6 +1062,9 @@ void __blk_put_request(struct request_queue *q, struct request *req) elv_completed_request(q, req); + /* this is a bio leak */ + WARN_ON(req->bio != NULL); + /* * Request may not have originated from ll_rw_blk. if not, * it didn't come out of our reserved rq pools diff --git a/block/blk-merge.c b/block/blk-merge.c index 5a244f05360f..e39cb24b7679 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -403,6 +403,8 @@ static int attempt_merge(struct request_queue *q, struct request *req, if (blk_rq_cpu_valid(next)) req->cpu = next->cpu; + /* owner-ship of bio passed from next to req */ + next->bio = NULL; __blk_put_request(q, next); return 1; } diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index ee9c67d7e1be..626ee274c5c4 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -214,21 +214,10 @@ static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq, return 0; } -/* - * unmap a request that was previously mapped to this sg_io_hdr. handles - * both sg and non-sg sg_io_hdr. - */ -static int blk_unmap_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr) -{ - blk_rq_unmap_user(rq->bio); - blk_put_request(rq); - return 0; -} - static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr, struct bio *bio) { - int r, ret = 0; + int ret = 0; /* * fill in all the output members @@ -253,12 +242,10 @@ static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr, ret = -EFAULT; } - rq->bio = bio; - r = blk_unmap_sghdr_rq(rq, hdr); - if (ret) - r = ret; + blk_rq_unmap_user(bio); + blk_put_request(rq); - return r; + return ret; } static int sg_io(struct request_queue *q, struct gendisk *bd_disk,