@@ -35,6 +35,7 @@
#include <linux/mlx5/srq.h>
#include <linux/slab.h>
#include <rdma/ib_umem.h>
+#include <rdma/ib_user_verbs.h>
#include "mlx5_ib.h"
#include "user.h"
@@ -84,10 +85,21 @@ static int create_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq,
int ncont;
u32 offset;
- if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd))) {
- mlx5_ib_dbg(dev, "failed copy udata\n");
- 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))) {
+ mlx5_ib_dbg(dev, "failed copy udata\n");
+ return -EFAULT;
+ }
+ } else {
+ if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd))) {
+ mlx5_ib_dbg(dev, "failed copy udata\n");
+ return -EFAULT;
+ }
+
+ if (ucmd.reserved != 0)
+ return -EINVAL;
}
+
srq->wq_sig = !!(ucmd.flags & MLX5_SRQ_FLAG_SIGNATURE);
srq->umem = ib_umem_get(pd->uobject->context, ucmd.buf_addr, buf_size,
@@ -110,6 +110,7 @@ struct mlx5_ib_create_srq {
__u64 buf_addr;
__u64 db_addr;
__u32 flags;
+ __u32 reserved; /* explicit padding (optional on i386) */
};
struct mlx5_ib_create_srq_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_srq get implicitly 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_srq \ 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 @@ -69,7 +68,6 @@ struct mlx5_ib_create_srq { __u64 db_addr; /* 8 8 */ __u32 flags; /* 16 4 */ - /* size: 20, cachelines: 1, members: 3 */ - /* last cacheline: 20 bytes */ + /* size: 24, cachelines: 1, members: 3 */ + /* padding: 4 */ + /* last cacheline: 24 bytes */ }; 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, the 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 and the uverb will fail. This patch makes create_srq_user() takes care of the input data size to handle the case where no padding was provided. This way, x86_64 kernel will be able to handle struct mlx5_ib_create_srq 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/srq.c | 18 +++++++++++++++--- drivers/infiniband/hw/mlx5/user.h | 1 + 2 files changed, 16 insertions(+), 3 deletions(-)