From: Alaa Hleihel alaa@nvidia.com
[ Upstream commit f0ae4afe3d35e67db042c58a52909e06262b740f ]
For the case of IB_MR_TYPE_DM the mr does doesn't have a umem, even though it is a user MR. This causes function mlx5_free_priv_descs() to think that it is a kernel MR, leading to wrongly accessing mr->descs that will get wrong values in the union which leads to attempt to release resources that were not allocated in the first place.
For example: DMA-API: mlx5_core 0000:08:00.1: device driver tries to free DMA memory it has not allocated [device address=0x0000000000000000] [size=0 bytes] WARNING: CPU: 8 PID: 1021 at kernel/dma/debug.c:961 check_unmap+0x54f/0x8b0 RIP: 0010:check_unmap+0x54f/0x8b0 Call Trace: debug_dma_unmap_page+0x57/0x60 mlx5_free_priv_descs+0x57/0x70 [mlx5_ib] mlx5_ib_dereg_mr+0x1fb/0x3d0 [mlx5_ib] ib_dereg_mr_user+0x60/0x140 [ib_core] uverbs_destroy_uobject+0x59/0x210 [ib_uverbs] uobj_destroy+0x3f/0x80 [ib_uverbs] ib_uverbs_cmd_verbs+0x435/0xd10 [ib_uverbs] ? uverbs_finalize_object+0x50/0x50 [ib_uverbs] ? lock_acquire+0xc4/0x2e0 ? lock_acquired+0x12/0x380 ? lock_acquire+0xc4/0x2e0 ? lock_acquire+0xc4/0x2e0 ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] ? lock_release+0x28a/0x400 ib_uverbs_ioctl+0xc0/0x140 [ib_uverbs] ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] __x64_sys_ioctl+0x7f/0xb0 do_syscall_64+0x38/0x90
Fix it by reorganizing the dereg flow and mlx5_ib_mr structure: - Move the ib_umem field into the user MRs structure in the union as it's applicable only there. - Function mlx5_ib_dereg_mr() will now call mlx5_free_priv_descs() only in case there isn't udata, which indicates that this isn't a user MR.
Fixes: f18ec4223117 ("RDMA/mlx5: Use a union inside mlx5_ib_mr") Link: https://lore.kernel.org/r/66bb1dd253c1fd7ceaa9fc411061eefa457b86fb.163758114... Signed-off-by: Alaa Hleihel alaa@nvidia.com Signed-off-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/mlx5/mlx5_ib.h | 6 +++--- drivers/infiniband/hw/mlx5/mr.c | 26 ++++++++++++-------------- 2 files changed, 15 insertions(+), 17 deletions(-)
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index bf20a388eabe1..6204ae2caef58 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -641,7 +641,6 @@ struct mlx5_ib_mr {
/* User MR data */ struct mlx5_cache_ent *cache_ent; - struct ib_umem *umem;
/* This is zero'd when the MR is allocated */ union { @@ -653,7 +652,7 @@ struct mlx5_ib_mr { struct list_head list; };
- /* Used only by kernel MRs (umem == NULL) */ + /* Used only by kernel MRs */ struct { void *descs; void *descs_alloc; @@ -675,8 +674,9 @@ struct mlx5_ib_mr { int data_length; };
- /* Used only by User MRs (umem != NULL) */ + /* Used only by User MRs */ struct { + struct ib_umem *umem; unsigned int page_shift; /* Current access_flags */ int access_flags; diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 22e2f4d79743d..69b2ce4c292ae 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1911,19 +1911,18 @@ mlx5_alloc_priv_descs(struct ib_device *device, return ret; }
-static void -mlx5_free_priv_descs(struct mlx5_ib_mr *mr) +static void mlx5_free_priv_descs(struct mlx5_ib_mr *mr) { - if (!mr->umem && mr->descs) { - struct ib_device *device = mr->ibmr.device; - int size = mr->max_descs * mr->desc_size; - struct mlx5_ib_dev *dev = to_mdev(device); + struct mlx5_ib_dev *dev = to_mdev(mr->ibmr.device); + int size = mr->max_descs * mr->desc_size;
- dma_unmap_single(&dev->mdev->pdev->dev, mr->desc_map, size, - DMA_TO_DEVICE); - kfree(mr->descs_alloc); - mr->descs = NULL; - } + if (!mr->descs) + return; + + dma_unmap_single(&dev->mdev->pdev->dev, mr->desc_map, size, + DMA_TO_DEVICE); + kfree(mr->descs_alloc); + mr->descs = NULL; }
int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) @@ -1999,7 +1998,8 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) if (mr->cache_ent) { mlx5_mr_cache_free(dev, mr); } else { - mlx5_free_priv_descs(mr); + if (!udata) + mlx5_free_priv_descs(mr); kfree(mr); } return 0; @@ -2086,7 +2086,6 @@ static struct mlx5_ib_mr *mlx5_ib_alloc_pi_mr(struct ib_pd *pd, if (err) goto err_free_in;
- mr->umem = NULL; kfree(in);
return mr; @@ -2213,7 +2212,6 @@ static struct ib_mr *__mlx5_ib_alloc_mr(struct ib_pd *pd, }
mr->ibmr.device = pd->device; - mr->umem = NULL;
switch (mr_type) { case IB_MR_TYPE_MEM_REG: