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path: root/drivers/block/nbd.c
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Diffstat (limited to 'drivers/block/nbd.c')
-rw-r--r--drivers/block/nbd.c32
1 files changed, 23 insertions, 9 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index ba405b55329f..807d24a2f1de 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -272,6 +272,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd)
int result, flags;
struct nbd_request request;
unsigned long size = blk_rq_bytes(req);
+ struct bio *bio;
u32 type;
if (req->cmd_type == REQ_TYPE_DRV_PRIV)
@@ -305,16 +306,20 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd)
return -EIO;
}
- if (type == NBD_CMD_WRITE) {
- struct req_iterator iter;
+ if (type != NBD_CMD_WRITE)
+ return 0;
+
+ flags = 0;
+ bio = req->bio;
+ while (bio) {
+ struct bio *next = bio->bi_next;
+ struct bvec_iter iter;
struct bio_vec bvec;
- /*
- * we are really probing at internals to determine
- * whether to set MSG_MORE or not...
- */
- rq_for_each_segment(bvec, req, iter) {
- flags = 0;
- if (!rq_iter_last(bvec, iter))
+
+ bio_for_each_segment(bvec, bio, iter) {
+ bool is_last = !next && bio_iter_last(bvec, iter);
+
+ if (is_last)
flags = MSG_MORE;
dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
cmd, bvec.bv_len);
@@ -325,7 +330,16 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd)
result);
return -EIO;
}
+ /*
+ * The completion might already have come in,
+ * so break for the last one instead of letting
+ * the iterator do it. This prevents use-after-free
+ * of the bio.
+ */
+ if (is_last)
+ break;
}
+ bio = next;
}
return 0;
}