From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ajay Kaher Subject: [PATCH] [v4.14.y] infiniband: fix race condition between infiniband mlx4, mlx5 driver and core dumping Date: Tue, 11 Jun 2019 02:22:17 +0530 Message-ID: <1560199937-23476-1-git-send-email-akaher@vmware.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Sender: stable-owner@vger.kernel.org To: aarcange@redhat.com, jannh@google.com, oleg@redhat.com, peterx@redhat.com, rppt@linux.ibm.com, jgg@mellanox.com, mhocko@suse.com Cc: yishaih@mellanox.com, dledford@redhat.com, sean.hefty@intel.com, hal.rosenstock@gmail.com, matanb@mellanox.com, leonro@mellanox.com, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, akaher@vmware.com, srivatsab@vmware.com, amakhalov@vmware.com List-Id: linux-rdma@vger.kernel.org This patch is the extension of following upstream commit to fix the race condition between get_task_mm() and core dumping for IB->mlx4 and IB->mlx5 drivers: commit 04f5866e41fb ("coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping")' Thanks to Jason for pointing this. Signed-off-by: Ajay Kaher --- drivers/infiniband/hw/mlx4/main.c | 4 +++- drivers/infiniband/hw/mlx5/main.c | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c index e2beb18..0299c06 100644 --- a/drivers/infiniband/hw/mlx4/main.c +++ b/drivers/infiniband/hw/mlx4/main.c @@ -1197,6 +1197,8 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) * mlx4_ib_vma_close(). */ down_write(&owning_mm->mmap_sem); + if (!mmget_still_valid(owning_mm)) + goto skip_mm; for (i = 0; i < HW_BAR_COUNT; i++) { vma = context->hw_bar_info[i].vma; if (!vma) @@ -1215,7 +1217,7 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) /* context going to be destroyed, should not access ops any more */ context->hw_bar_info[i].vma->vm_ops = NULL; } - +skip_mm: up_write(&owning_mm->mmap_sem); mmput(owning_mm); put_task_struct(owning_process); diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index 13a9206..3fbe396 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -1646,6 +1646,8 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) * mlx5_ib_vma_close. */ down_write(&owning_mm->mmap_sem); + if (!mmget_still_valid(owning_mm)) + goto skip_mm; mutex_lock(&context->vma_private_list_mutex); list_for_each_entry_safe(vma_private, n, &context->vma_private_list, list) { @@ -1662,6 +1664,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) kfree(vma_private); } mutex_unlock(&context->vma_private_list_mutex); +skip_mm: up_write(&owning_mm->mmap_sem); mmput(owning_mm); put_task_struct(owning_process); -- 2.7.4