diff options
Diffstat (limited to 'system/xen/xsa/xsa231-4.9.patch')
| -rw-r--r-- | system/xen/xsa/xsa231-4.9.patch | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/system/xen/xsa/xsa231-4.9.patch b/system/xen/xsa/xsa231-4.9.patch new file mode 100644 index 0000000000..251165e6bd --- /dev/null +++ b/system/xen/xsa/xsa231-4.9.patch @@ -0,0 +1,108 @@ +From: George Dunlap <george.dunlap@citrix.com> +Subject: xen/mm: make sure node is less than MAX_NUMNODES + +The output of MEMF_get_node(memflags) can be as large as nodeid_t can +hold (currently 255). This is then used as an index to arrays of size +MAX_NUMNODE, which is 64 on x86 and 1 on ARM, can be passed in by an +untrusted guest (via memory_exchange and increase_reservation) and is +not currently bounds-checked. + +Check the value in page_alloc.c before using it, and also check the +value in the hypercall call sites and return -EINVAL if appropriate. +Don't permit domains other than the hardware or control domain to +allocate node-constrained memory. + +This is XSA-231. + +Reported-by: Matthew Daley <mattd@bugfuzz.com> +Signed-off-by: George Dunlap <george.dunlap@citrix.com> +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> + +--- a/xen/common/memory.c ++++ b/xen/common/memory.c +@@ -411,6 +411,31 @@ static void decrease_reservation(struct + a->nr_done = i; + } + ++static bool propagate_node(unsigned int xmf, unsigned int *memflags) ++{ ++ const struct domain *currd = current->domain; ++ ++ BUILD_BUG_ON(XENMEMF_get_node(0) != NUMA_NO_NODE); ++ BUILD_BUG_ON(MEMF_get_node(0) != NUMA_NO_NODE); ++ ++ if ( XENMEMF_get_node(xmf) == NUMA_NO_NODE ) ++ return true; ++ ++ if ( is_hardware_domain(currd) || is_control_domain(currd) ) ++ { ++ if ( XENMEMF_get_node(xmf) >= MAX_NUMNODES ) ++ return false; ++ ++ *memflags |= MEMF_node(XENMEMF_get_node(xmf)); ++ if ( xmf & XENMEMF_exact_node_request ) ++ *memflags |= MEMF_exact_node; ++ } ++ else if ( xmf & XENMEMF_exact_node_request ) ++ return false; ++ ++ return true; ++} ++ + static long memory_exchange(XEN_GUEST_HANDLE_PARAM(xen_memory_exchange_t) arg) + { + struct xen_memory_exchange exch; +@@ -483,6 +508,12 @@ static long memory_exchange(XEN_GUEST_HA + } + } + ++ if ( unlikely(!propagate_node(exch.out.mem_flags, &memflags)) ) ++ { ++ rc = -EINVAL; ++ goto fail_early; ++ } ++ + d = rcu_lock_domain_by_any_id(exch.in.domid); + if ( d == NULL ) + { +@@ -501,7 +532,6 @@ static long memory_exchange(XEN_GUEST_HA + d, + XENMEMF_get_address_bits(exch.out.mem_flags) ? : + (BITS_PER_LONG+PAGE_SHIFT))); +- memflags |= MEMF_node(XENMEMF_get_node(exch.out.mem_flags)); + + for ( i = (exch.nr_exchanged >> in_chunk_order); + i < (exch.in.nr_extents >> in_chunk_order); +@@ -864,12 +894,8 @@ static int construct_memop_from_reservat + } + read_unlock(&d->vnuma_rwlock); + } +- else +- { +- a->memflags |= MEMF_node(XENMEMF_get_node(r->mem_flags)); +- if ( r->mem_flags & XENMEMF_exact_node_request ) +- a->memflags |= MEMF_exact_node; +- } ++ else if ( unlikely(!propagate_node(r->mem_flags, &a->memflags)) ) ++ return -EINVAL; + + return 0; + } +--- a/xen/common/page_alloc.c ++++ b/xen/common/page_alloc.c +@@ -706,9 +706,13 @@ static struct page_info *alloc_heap_page + if ( node >= MAX_NUMNODES ) + node = cpu_to_node(smp_processor_id()); + } ++ else if ( unlikely(node >= MAX_NUMNODES) ) ++ { ++ ASSERT_UNREACHABLE(); ++ return NULL; ++ } + first_node = node; + +- ASSERT(node < MAX_NUMNODES); + ASSERT(zone_lo <= zone_hi); + ASSERT(zone_hi < NR_ZONES); + |