Setting UBLK_F_USER_RECOVERY_REISSUE without also setting UBLK_F_USER_RECOVERY is currently silently equivalent to not setting any recovery flags at all, even though that's obviously not intended. Check for this case and fail add_dev (with a paranoid warning to aid debugging any program which might rely on the old behavior) with EINVAL if it is detected. Signed-off-by: Uday Shankar <ushankar@xxxxxxxxxxxxxxx> Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx> --- drivers/block/ublk_drv.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index a6c8e5cc6051..318a4dfe8266 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -62,6 +62,9 @@ | UBLK_F_USER_COPY \ | UBLK_F_ZONED) +#define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \ + | UBLK_F_USER_RECOVERY_REISSUE) + /* All UBLK_PARAM_TYPE_* should be included here */ #define UBLK_PARAM_TYPE_ALL \ (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD | \ @@ -2372,6 +2375,14 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) else if (!(info.flags & UBLK_F_UNPRIVILEGED_DEV)) return -EPERM; + /* forbid nonsense combinations of recovery flags */ + if ((info.flags & UBLK_F_USER_RECOVERY_REISSUE) && + !(info.flags & UBLK_F_USER_RECOVERY)) { + pr_warn("%s: invalid recovery flags %llx\n", __func__, + info.flags & UBLK_F_ALL_RECOVERY_FLAGS); + return -EINVAL; + } + /* * unprivileged device can't be trusted, but RECOVERY and * RECOVERY_REISSUE still may hang error handling, so can't -- 2.34.1