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 [1]. 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. [1] https://lore.kernel.org/linux-rdma/20201119093523.7588-1-zhudi21@xxxxxxxxxx/raw Fixes: d37498417947 ("i40iw: add files for iwarp interface") Cc: stable@xxxxxxxxxx Reported-by: Di Zhu <zhudi21@xxxxxxxxxx> Signed-off-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx> --- drivers/infiniband/hw/i40iw/i40iw_main.c | 5 ---- drivers/infiniband/hw/i40iw/i40iw_verbs.c | 37 +++++----------------------- 2 files changed, 7 insertions(+), 35 deletions(-) diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c index 2408b27..584932d 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 581ecba..533f3ca 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); } /** -- 1.7.1
