__ublk_check_and_get_req() checks that the passed in offset is within the data length of the specified ublk request. However, only user copy (ublk_check_and_get_req()) supports accessing ublk request data at a nonzero offset. Zero-copy buffer registration (ublk_register_io_buf()) always passes 0 for the offset, so the check is unnecessary. Move the check from __ublk_check_and_get_req() to ublk_check_and_get_req().
Signed-off-by: Caleb Sander Mateos <[email protected]> --- drivers/block/ublk_drv.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 273d580ddc46..7fa0a9f0bfae 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -252,11 +252,11 @@ struct ublk_params_header { static void ublk_io_release(void *priv); static void ublk_stop_dev_unlocked(struct ublk_device *ub); static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq); static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub, - u16 q_id, u16 tag, struct ublk_io *io, size_t offset); + u16 q_id, u16 tag, struct ublk_io *io); static inline unsigned int ublk_req_build_flags(struct request *req); static inline struct ublksrv_io_desc * ublk_get_iod(const struct ublk_queue *ubq, unsigned tag) { @@ -2245,11 +2245,11 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd, int ret; if (!ublk_dev_support_zero_copy(ub)) return -EINVAL; - req = __ublk_check_and_get_req(ub, q_id, tag, io, 0); + req = __ublk_check_and_get_req(ub, q_id, tag, io); if (!req) return -EINVAL; ret = io_buffer_register_bvec(cmd, req, ublk_io_release, index, issue_flags); @@ -2539,11 +2539,11 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd, __func__, cmd_op, tag, ret, io ? io->flags : 0); return ret; } static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub, - u16 q_id, u16 tag, struct ublk_io *io, size_t offset) + u16 q_id, u16 tag, struct ublk_io *io) { struct request *req; /* * can't use io->req in case of concurrent UBLK_IO_COMMIT_AND_FETCH_REQ, @@ -2560,13 +2560,10 @@ static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub, goto fail_put; if (!ublk_rq_has_data(req)) goto fail_put; - if (offset > blk_rq_bytes(req)) - goto fail_put; - return req; fail_put: ublk_put_req_ref(io, req); return NULL; } @@ -2644,14 +2641,19 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir) if (tag >= ub->dev_info.queue_depth) return -EINVAL; io = &ubq->ios[tag]; - req = __ublk_check_and_get_req(ub, q_id, tag, io, buf_off); + req = __ublk_check_and_get_req(ub, q_id, tag, io); if (!req) return -EINVAL; + if (buf_off > blk_rq_bytes(req)) { + ret = -EINVAL; + goto out; + } + if (!ublk_check_ubuf_dir(req, dir)) { ret = -EACCES; goto out; } -- 2.45.2
