@@ -32,6 +32,7 @@
#include <linux/kref.h>
#include <rdma/ib_umem.h>
+#include <rdma/ib_user_verbs.h>
#include "mlx5_ib.h"
#include "user.h"
@@ -607,8 +608,16 @@ static int create_cq_user(struct mlx5_ib_dev *dev, struct ib_udata *udata,
int ncont;
int err;
- if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd)))
- return -EFAULT;
+ if (udata->inlen - sizeof(struct ib_uverbs_cmd_hdr) < sizeof(ucmd)) {
+ if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd) - sizeof(ucmd.reserved)))
+ return -EFAULT;
+ } else {
+ if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd)))
+ return -EFAULT;
+
+ if (ucmd.reserved != 0)
+ return -EINVAL;
+ }
if (ucmd.cqe_size != 64 && ucmd.cqe_size != 128)
return -EINVAL;
@@ -91,6 +91,7 @@ struct mlx5_ib_create_cq {
__u64 buf_addr;
__u64 db_addr;
__u32 cqe_size;
+ __u32 reserved; /* explicit padding (optional on i386) */
};
struct mlx5_ib_create_cq_resp {
i386 ABI disagree with most other ABIs regarding alignment of data type larger than 4 bytes: on most ABIs a padding must be added at end of the structures, while it is not required on i386. So for most ABI struct mlx5_ib_create_cq get padded to be aligned on a 8 bytes multiple, while for i386, such padding is not added. Tool pahole could be used to find such implicit padding: $ pahole --anon_include \ --nested_anon_include \ --recursive \ --class_name mlx5_ib_create_cq \ drivers/infiniband/hw/mlx5/mlx5_ib.o Then, structure layout can be compared between i386 and x86_64: +++ obj-i386/drivers/infiniband/hw/mlx5/mlx5_ib.o.pahole.txt 2014-03-28 11:43:07.386413682 +0100 --- obj-x86_64/drivers/infiniband/hw/mlx5/mlx5_ib.o.pahole.txt 2014-03-27 13:06:17.788472721 +0100 @@ -34,9 +34,8 @@ struct mlx5_ib_create_cq { __u64 db_addr; /* 8 8 */ __u32 cqe_size; /* 16 4 */ - /* size: 20, cachelines: 1, members: 3 */ - /* last cacheline: 20 bytes */ + /* size: 24, cachelines: 1, members: 3 */ + /* padding: 4 */ + /* last cacheline: 24 bytes */ }; This ABI disagreement will make an x86_64 kernel try to read past the buffer provided by an i386 binary. When boundary check will be implemented, a x86_64 kernel will refuse to read past the i386 userspace provided buffer and the uverb will fail. Anyway, if the structure lay in memory on a page boundary and next page is not mapped, ib_copy_from_udata() will fail when trying to read the 4 bytes of padding and the uverb will fail. This patch makes create_cq_user() takes care of the input data size to handle the case where no padding is provided. This way, x86_64 kernel will be able to handle struct mlx5_ib_create_cq as sent by unpatched and patched i386 libmlx5. Link: http://marc.info/?i=cover.1399216475.git.ydroneaud@opteya.com Cc: stable@vger.kernel.org Fixes: e126ba97dba9e ('mlx5: Add driver for Mellanox Connect-IB adapter') Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> --- drivers/infiniband/hw/mlx5/cq.c | 13 +++++++++++-- drivers/infiniband/hw/mlx5/user.h | 1 + 2 files changed, 12 insertions(+), 2 deletions(-)