Commit ad9a3668 authored by Majd Dibbiny's avatar Majd Dibbiny Committed by Jason Gunthorpe

IB/mlx5: Serialize access to the VMA list

User-space applications can do mmap and munmap directly at
any time.

Since the VMA list is not protected with a mutex, concurrent
accesses to the VMA list from the mmap and munmap can cause
data corruption. Add a mutex around the list.

Cc: <stable@vger.kernel.org> # v4.7
Fixes: 7c2344c3 ("IB/mlx5: Implements disassociate_ucontext API")
Reviewed-by: default avatarYishai Hadas <yishaih@mellanox.com>
Signed-off-by: default avatarMajd Dibbiny <majd@mellanox.com>
Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 4c009af4
......@@ -1463,6 +1463,7 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
}
INIT_LIST_HEAD(&context->vma_private_list);
mutex_init(&context->vma_private_list_mutex);
INIT_LIST_HEAD(&context->db_page_list);
mutex_init(&context->db_page_mutex);
......@@ -1624,7 +1625,9 @@ static void mlx5_ib_vma_close(struct vm_area_struct *area)
* mlx5_ib_disassociate_ucontext().
*/
mlx5_ib_vma_priv_data->vma = NULL;
mutex_lock(mlx5_ib_vma_priv_data->vma_private_list_mutex);
list_del(&mlx5_ib_vma_priv_data->list);
mutex_unlock(mlx5_ib_vma_priv_data->vma_private_list_mutex);
kfree(mlx5_ib_vma_priv_data);
}
......@@ -1644,10 +1647,13 @@ static int mlx5_ib_set_vma_data(struct vm_area_struct *vma,
return -ENOMEM;
vma_prv->vma = vma;
vma_prv->vma_private_list_mutex = &ctx->vma_private_list_mutex;
vma->vm_private_data = vma_prv;
vma->vm_ops = &mlx5_ib_vm_ops;
mutex_lock(&ctx->vma_private_list_mutex);
list_add(&vma_prv->list, vma_head);
mutex_unlock(&ctx->vma_private_list_mutex);
return 0;
}
......@@ -1690,6 +1696,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
* mlx5_ib_vma_close.
*/
down_write(&owning_mm->mmap_sem);
mutex_lock(&context->vma_private_list_mutex);
list_for_each_entry_safe(vma_private, n, &context->vma_private_list,
list) {
vma = vma_private->vma;
......@@ -1704,6 +1711,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
list_del(&vma_private->list);
kfree(vma_private);
}
mutex_unlock(&context->vma_private_list_mutex);
up_write(&owning_mm->mmap_sem);
mmput(owning_mm);
put_task_struct(owning_process);
......
......@@ -115,6 +115,8 @@ enum {
struct mlx5_ib_vma_private_data {
struct list_head list;
struct vm_area_struct *vma;
/* protect vma_private_list add/del */
struct mutex *vma_private_list_mutex;
};
struct mlx5_ib_ucontext {
......@@ -129,6 +131,8 @@ struct mlx5_ib_ucontext {
/* Transport Domain number */
u32 tdn;
struct list_head vma_private_list;
/* protect vma_private_list add/del */
struct mutex vma_private_list_mutex;
unsigned long upd_xlt_page;
/* protect ODP/KSM */
......
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