For SQE128, sqe->cmd provides 80 bytes for uring_cmd. Add macro to check if size of user struct does not exceed 80 bytes at compile time. User doesn't have to track this manually during development. Replace io_uring_sqe_cmd() with IO_URING_SQE_CMD() which checks struct size for 16 bytes cmd. Signed-off-by: Govindarajulu Varadarajan --- drivers/block/ublk_drv.c | 14 ++++++++------ drivers/nvme/host/ioctl.c | 2 +- fs/fuse/dev_uring.c | 6 ++++-- include/linux/io_uring/cmd.h | 15 +++++++++++---- 4 files changed, 24 insertions(+), 13 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 4265b7610c95..7c8a23709efa 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -3155,7 +3155,7 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd, unsigned int issue_flags) { /* May point to userspace-mapped memory */ - const struct ublksrv_io_cmd *ub_src = io_uring_sqe_cmd(cmd->sqe); + const struct ublksrv_io_cmd *ub_src = IO_URING_SQE_CMD(cmd->sqe, struct ublksrv_io_cmd); u16 buf_idx = UBLK_INVALID_BUF_IDX; struct ublk_device *ub = cmd->file->private_data; struct ublk_queue *ubq; @@ -3735,7 +3735,7 @@ static int ublk_validate_batch_fetch_cmd(struct ublk_batch_io_data *data) static int ublk_handle_non_batch_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) { - const struct ublksrv_io_cmd *ub_cmd = io_uring_sqe_cmd(cmd->sqe); + const struct ublksrv_io_cmd *ub_cmd = IO_URING_SQE_CMD(cmd->sqe, struct ublksrv_io_cmd); struct ublk_device *ub = cmd->file->private_data; unsigned tag = READ_ONCE(ub_cmd->tag); unsigned q_id = READ_ONCE(ub_cmd->q_id); @@ -3764,7 +3764,7 @@ static int ublk_handle_non_batch_cmd(struct io_uring_cmd *cmd, static int ublk_ch_batch_io_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) { - const struct ublk_batch_io *uc = io_uring_sqe_cmd(cmd->sqe); + const struct ublk_batch_io *uc = IO_URING_SQE_CMD(cmd->sqe, struct ublk_batch_io); struct ublk_device *ub = cmd->file->private_data; struct ublk_batch_io_data data = { .ub = ub, @@ -4653,7 +4653,8 @@ static int ublk_ctrl_del_dev(struct ublk_device **p_ub, bool wait) static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); + const struct ublksrv_ctrl_cmd *header = IO_URING_SQE128_CMD(cmd->sqe, + struct ublksrv_ctrl_cmd); pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n", __func__, cmd->cmd_op, header->dev_id, header->queue_id, @@ -5061,7 +5062,7 @@ static int ublk_char_dev_permission(struct ublk_device *ub, static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub, struct io_uring_cmd *cmd) { - struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)io_uring_sqe_cmd(cmd->sqe); + struct ublksrv_ctrl_cmd *header = IO_URING_SQE128_CMD(cmd->sqe, struct ublksrv_ctrl_cmd); bool unprivileged = ub->dev_info.flags & UBLK_F_UNPRIVILEGED_DEV; void __user *argp = (void __user *)(unsigned long)header->addr; char *dev_path = NULL; @@ -5152,7 +5153,8 @@ static bool ublk_ctrl_uring_cmd_may_sleep(u32 cmd_op) static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); + const struct ublksrv_ctrl_cmd *header = IO_URING_SQE128_CMD(cmd->sqe, + struct ublksrv_ctrl_cmd); struct ublk_device *ub = NULL; u32 cmd_op = cmd->cmd_op; int ret = -EINVAL; diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c index fb62633ccbb0..90c49bb727ad 100644 --- a/drivers/nvme/host/ioctl.c +++ b/drivers/nvme/host/ioctl.c @@ -447,7 +447,7 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns, struct io_uring_cmd *ioucmd, unsigned int issue_flags, bool vec) { struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd); - const struct nvme_uring_cmd *cmd = io_uring_sqe_cmd(ioucmd->sqe); + const struct nvme_uring_cmd *cmd = IO_URING_SQE128_CMD(ioucmd->sqe, struct nvme_uring_cmd); struct request_queue *q = ns ? ns->queue : ctrl->admin_q; struct nvme_uring_data d; struct nvme_command c; diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c index 5ceb217ced1b..7dddba72f406 100644 --- a/fs/fuse/dev_uring.c +++ b/fs/fuse/dev_uring.c @@ -879,7 +879,8 @@ static int fuse_ring_ent_set_commit(struct fuse_ring_ent *ent) static int fuse_uring_commit_fetch(struct io_uring_cmd *cmd, int issue_flags, struct fuse_conn *fc) { - const struct fuse_uring_cmd_req *cmd_req = io_uring_sqe_cmd(cmd->sqe); + const struct fuse_uring_cmd_req *cmd_req = IO_URING_SQE128_CMD(cmd->sqe, + struct fuse_uring_cmd_req); struct fuse_ring_ent *ent; int err; struct fuse_ring *ring = fc->ring; @@ -1083,7 +1084,8 @@ fuse_uring_create_ring_ent(struct io_uring_cmd *cmd, static int fuse_uring_register(struct io_uring_cmd *cmd, unsigned int issue_flags, struct fuse_conn *fc) { - const struct fuse_uring_cmd_req *cmd_req = io_uring_sqe_cmd(cmd->sqe); + const struct fuse_uring_cmd_req *cmd_req = IO_URING_SQE128_CMD(cmd->sqe, + struct fuse_uring_cmd_req); struct fuse_ring *ring = smp_load_acquire(&fc->ring); struct fuse_ring_queue *queue; struct fuse_ring_ent *ent; diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h index 375fd048c4cb..e8fd93e90cde 100644 --- a/include/linux/io_uring/cmd.h +++ b/include/linux/io_uring/cmd.h @@ -20,10 +20,17 @@ struct io_uring_cmd { u8 unused[8]; }; -static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe) -{ - return sqe->cmd; -} +#define IO_URING_SQE128_CMD(sqe, type) ({ \ + BUILD_BUG_ON(sizeof(type) > ((2 * sizeof(struct io_uring_sqe)) - \ + offsetof(struct io_uring_sqe, cmd))); \ + (type *)(sqe)->cmd; \ +}) + +#define IO_URING_SQE_CMD(sqe, type) ({ \ + BUILD_BUG_ON(sizeof(type) > ((sizeof(struct io_uring_sqe)) - \ + offsetof(struct io_uring_sqe, cmd))); \ + (type *)(sqe)->cmd; \ +}) static inline void io_uring_cmd_private_sz_check(size_t cmd_sz) { -- 2.52.0