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| author | Boaz Harrosh <bharrosh@panasas.com> | 2009-03-24 12:35:07 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2009-03-26 11:01:23 +0100 |
| commit | 1cd96c242a829d52f7a5ae98f554ca9775429685 (patch) | |
| tree | 018d3ab9fa0d6e2bcd739483ac2693f6f71db96b | |
| parent | f028f3b2f987ebc61cef382ab7a5c449917b728e (diff) | |
| download | linux-1cd96c242a829d52f7a5ae98f554ca9775429685.tar.gz linux-1cd96c242a829d52f7a5ae98f554ca9775429685.tar.bz2 linux-1cd96c242a829d52f7a5ae98f554ca9775429685.zip | |
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 <bharrosh@panasas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| -rw-r--r-- | block/blk-core.c | 3 | ||||
| -rw-r--r-- | block/blk-merge.c | 2 | ||||
| -rw-r--r-- | 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, |