| Message ID | 66bb1dd253c1fd7ceaa9fc411061eefa457b86fb.1637581144.git.leonro@nvidia.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Jason Gunthorpe |
| Headers | show |
| Series | [rdma-rc,v1] RDMA/mlx5: Fix releasing unallocated memory in dereg MR flow | expand |
On Mon, Nov 22, 2021 at 01:41:51PM +0200, Leon Romanovsky wrote: > From: Alaa Hleihel <alaa@nvidia.com> > > After the cited patch, and for the case of IB_MR_TYPE_DM that doesn't > have a umem (even though it is a user MR), function mlx5_free_priv_descs() > will think that it's 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 on 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") > Signed-off-by: Alaa Hleihel <alaa@nvidia.com> > Signed-off-by: Leon Romanovsky <leonro@nvidia.com> > --- > v1: > * Different implementation > v0: https://lore.kernel.org/linux-rdma/e13b7014857ea296285ee5cfcdaaada9007f6978.1634638695.git.leonro@nvidia.com/ > --- > drivers/infiniband/hw/mlx5/mlx5_ib.h | 6 +++--- > drivers/infiniband/hw/mlx5/mr.c | 26 ++++++++++++-------------- > 2 files changed, 15 insertions(+), 17 deletions(-) Applied to for-rc, thanks Jason
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index e636e954f6bf..4a7a56ed740b 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -664,7 +664,6 @@ 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 { @@ -676,7 +675,7 @@ 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; @@ -697,8 +696,9 @@ 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 157d862fb864..63e2129f1142 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1904,19 +1904,18 @@ 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) @@ -1992,7 +1991,8 @@ 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; @@ -2079,7 +2079,6 @@ 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; @@ -2206,7 +2205,6 @@ 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: