From: Govindarajulu Varadarajan ublk_ctrl_cmd_dump() accesses (header *)sqe->cmd before IO_URING_F_SQE128 flag check. This could cause out of boundary memory access. Move the SQE128 flag check earlier in ublk_ctrl_uring_cmd() to return -EINVAL immediately if the flag is not set. Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver") Signed-off-by: Govindarajulu Varadarajan Reviewed-by: Caleb Sander Mateos Reviewed-by: Ming Lei --- drivers/block/ublk_drv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 5efaf53261ce..01088194c8d3 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -5219,14 +5219,14 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, if (ublk_ctrl_uring_cmd_may_sleep(cmd_op) && issue_flags & IO_URING_F_NONBLOCK) return -EAGAIN; - ublk_ctrl_cmd_dump(cmd); - if (!(issue_flags & IO_URING_F_SQE128)) - goto out; + return -EINVAL; + + ublk_ctrl_cmd_dump(cmd); ret = ublk_check_cmd_op(cmd_op); if (ret) goto out; -- 2.45.2