The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2ed381439e89fa6d1a0839ef45ccd45d99d8e915 Mon Sep 17 00:00:00 2001

From: Shiraz Saleem shiraz.saleem@intel.com Date: Tue, 24 Nov 2020 18:56:16 -0600 Subject: [PATCH] RDMA/i40iw: Address an mmap handler exploit in i40iw

i40iw_mmap manipulates the vma->vm_pgoff to differentiate a push page mmap vs a doorbell mmap, and uses it to compute the pfn in remap_pfn_range without any validation. This is vulnerable to an mmap exploit as described in: https://lore.kernel.org/r/20201119093523.7588-1-zhudi21@huawei.com

The push feature is disabled in the driver currently and therefore no push mmaps are issued from user-space. The feature does not work as expected in the x722 product.

Remove the push module parameter and all VMA attribute manipulations for this feature in i40iw_mmap. Update i40iw_mmap to only allow DB user mmapings at offset = 0. Check vm_pgoff for zero and if the mmaps are bound to a single page.

Cc: stable@kernel.org Fixes: d37498417947 ("i40iw: add files for iwarp interface") Link: https://lore.kernel.org/r/20201125005616.1800-2-shiraz.saleem@intel.com Reported-by: Di Zhu zhudi21@huawei.com Signed-off-by: Shiraz Saleem shiraz.saleem@intel.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com

diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c index 2408b279e4c2..584932d3cc44 100644 --- a/drivers/infiniband/hw/i40iw/i40iw_main.c +++ b/drivers/infiniband/hw/i40iw/i40iw_main.c @@ -54,10 +54,6 @@ #define DRV_VERSION __stringify(DRV_VERSION_MAJOR) "." \ __stringify(DRV_VERSION_MINOR) "." __stringify(DRV_VERSION_BUILD)

-static int push_mode; -module_param(push_mode, int, 0644); -MODULE_PARM_DESC(push_mode, "Low latency mode: 0=disabled (default), 1=enabled)"); - static int debug; module_param(debug, int, 0644); MODULE_PARM_DESC(debug, "debug flags: 0=disabled (default), 0x7fffffff=all"); @@ -1580,7 +1576,6 @@ static enum i40iw_status_code i40iw_setup_init_state(struct i40iw_handler *hdl, if (status) goto exit; iwdev->obj_next = iwdev->obj_mem; - iwdev->push_mode = push_mode;

init_waitqueue_head(&iwdev->vchnl_waitq); init_waitqueue_head(&dev->vf_reqs); diff --git a/drivers/infiniband/hw/i40iw/i40iw_verbs.c b/drivers/infiniband/hw/i40iw/i40iw_verbs.c index 581ecbadf586..533f3caecb7a 100644 --- a/drivers/infiniband/hw/i40iw/i40iw_verbs.c +++ b/drivers/infiniband/hw/i40iw/i40iw_verbs.c @@ -167,39 +167,16 @@ static void i40iw_dealloc_ucontext(struct ib_ucontext *context) */ static int i40iw_mmap(struct ib_ucontext *context, struct vm_area_struct *vma) { - struct i40iw_ucontext *ucontext; - u64 db_addr_offset, push_offset, pfn; - - ucontext = to_ucontext(context); - if (ucontext->iwdev->sc_dev.is_pf) { - db_addr_offset = I40IW_DB_ADDR_OFFSET; - push_offset = I40IW_PUSH_OFFSET; - if (vma->vm_pgoff) - vma->vm_pgoff += I40IW_PF_FIRST_PUSH_PAGE_INDEX - 1; - } else { - db_addr_offset = I40IW_VF_DB_ADDR_OFFSET; - push_offset = I40IW_VF_PUSH_OFFSET; - if (vma->vm_pgoff) - vma->vm_pgoff += I40IW_VF_FIRST_PUSH_PAGE_INDEX - 1; - } + struct i40iw_ucontext *ucontext = to_ucontext(context); + u64 dbaddr;

- vma->vm_pgoff += db_addr_offset >> PAGE_SHIFT; - - if (vma->vm_pgoff == (db_addr_offset >> PAGE_SHIFT)) { - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - } else { - if ((vma->vm_pgoff - (push_offset >> PAGE_SHIFT)) % 2) - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - else - vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); - } + if (vma->vm_pgoff || vma->vm_end - vma->vm_start != PAGE_SIZE) + return -EINVAL;

- pfn = vma->vm_pgoff + - (pci_resource_start(ucontext->iwdev->ldev->pcidev, 0) >> - PAGE_SHIFT); + dbaddr = I40IW_DB_ADDR_OFFSET + pci_resource_start(ucontext->iwdev->ldev->pcidev, 0);

- return rdma_user_mmap_io(context, vma, pfn, PAGE_SIZE, - vma->vm_page_prot, NULL); + return rdma_user_mmap_io(context, vma, dbaddr >> PAGE_SHIFT, PAGE_SIZE, + pgprot_noncached(vma->vm_page_prot), NULL); }

/**