CVE-2014-8159 kernel: infiniband: uverbs: unprotected physical memory access

[Shachar Raindel <raindel-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>]

Hi,

It was found that the Linux kernel's InfiniBand/RDMA subsystem did not properly sanitize input parameters while registering memory regions from user space via the (u)verbs API. A local user with access to a /dev/infiniband/uverbsX device could use this flaw to crash the system or, potentially, escalate their privileges on the system.

The issue has been assigned CVE-2014-8159.

The issue exists in the InfiniBand/RDMA/iWARP drivers since Linux Kernel version 2.6.13.

Mellanox OFED 2.4-1.0.4 fixes the issue. Available from:
http://www.mellanox.com/page/products_dyn?product_family=26&mtag=linux_sw_drivers 

RedHat errata: https://access.redhat.com/security/cve/CVE-2014-8159
Canonical errata: http://people.canonical.com/~ubuntu-security/cve/2014/CVE-2014-8159.html
Novell (Suse) bug tracking: https://bugzilla.novell.com/show_bug.cgi?id=914742


The following patch fixes the issue:

--------------- 8< ------------------------------

>From d4d68430d4a12c569e28b4f4468284ea22111186 Mon Sep 17 00:00:00 2001
From: Shachar Raindel <raindel-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Date: Sun, 04 Jan 2015 18:30:32 +0200
Subject: [PATCH] IB/core: Prevent integer overflow in ib_umem_get address arithmetic

Properly verify that the resulting page aligned end address is larger
than both the start address and the length of the memory area
requested.

Both the start and length arguments for ib_umem_get are controlled by
the user. A misbehaving user can provide values which will cause an
integer overflow when calculating the page aligned end address.

This overflow can cause also miscalculation of the number of pages
mapped, and additional logic issues.

Signed-off-by: Shachar Raindel <raindel-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Jack Morgenstein <jackm-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index aec7a6a..8c014b5 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -99,6 +99,14 @@
 	if (dmasync)
 		dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
 
+	/*
+	 * If the combination of the addr and size requested for this memory
+	 * region causes an integer overflow, return error.
+	 */
+	if ((PAGE_ALIGN(addr + size) <= size) ||
+	    (PAGE_ALIGN(addr + size) <= addr))
+		return ERR_PTR(-EINVAL);
+
 	if (!can_do_mlock())
 		return ERR_PTR(-EPERM);

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