# \[PATCH v1 2/5\] IB/uverbs: ex\_query\_device: check request's comp\_mask - Subsystems: INFINIBAND SUBSYSTEM, THE REST - Maintainers: Jason Gunthorpe, Leon Romanovsky, Linus Torvalds - List: linux-api - 1 message, 1 author - Page: https://ratatoskr.run/linux-api/2015/01/13329039/t ## \[PATCH v1 2/5\] IB/uverbs: ex\_query\_device: check request's comp\_mask - From: Yann Droneaud \ - Date: 2015-01-29 17:59:59 - Message: https://ratatoskr.run/linux-api/2015/01/13329039.md ```text This patch ensures the extended QUERY_DEVICE uverbs request's comp_mask has only known and supported bits (currently none). If userspace set unknown features bits, -EINVAL will be returned, ensuring current programs are not allowed to set random feature bits: such bits could enable new extended features in future kernel versions and those features can trigger a behavior not unsupported by the older programs or make the newer kernels return an error for a request which was valid on older kernels. Additionally, returning an error for unsupported feature would allow userspace to probe/discover which extended features are currently supported by a kernel. Link: http://mid.gmane.org/cover.1422553023.git.ydroneaud-RlY5vtjFyJ3QT0dZR+AlfA@public.gmane.org Cc: Sagi Grimberg Cc: Shachar Raindel Cc: Eli Cohen Cc: Haggai Eran Signed-off-by: Yann Droneaud --- drivers/infiniband/core/uverbs_cmd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 6ef06a9b4362..fbcc54b86795 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -3312,6 +3312,9 @@ int ib_uverbs_ex_query_device(struct ib_uverbs_file *file, if (err) return err; + if (cmd.comp_mask) + return -EINVAL; + if (cmd.reserved) return -EINVAL; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ```