qubes-linux-kernel/patches.xen/xsa270.patch
Marek Marczykowski-Górecki ce8314b4e1
Apply XSA 270 fix
2018-08-07 14:07:15 +02:00

50 lines
1.8 KiB
Diff

From: Jan Beulich <jbeulich@suse.com>
Subject: xen-netback: fix input validation in xenvif_set_hash_mapping()
Both len and off are frontend specified values, so we need to make
sure there's no overflow when adding the two for the bounds check. We
also want to avoid undefined behavior and hence use off to index into
->hash.mapping[] only after bounds checking. This at the same time
allows to take care of not applying off twice for the bounds checking
against vif->num_queues.
It is also insufficient to bounds check copy_op.len, as this is len
truncated to 16 bits.
This is XSA-270.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Tested-by: Paul Durrant <paul.durrant@citrix.com>
--- a/drivers/net/xen-netback/hash.c
+++ b/drivers/net/xen-netback/hash.c
@@ -332,20 +332,22 @@ u32 xenvif_set_hash_mapping_size(struct
u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
u32 off)
{
- u32 *mapping = &vif->hash.mapping[off];
+ u32 *mapping = vif->hash.mapping;
struct gnttab_copy copy_op = {
.source.u.ref = gref,
.source.domid = vif->domid,
- .dest.u.gmfn = virt_to_gfn(mapping),
.dest.domid = DOMID_SELF,
- .dest.offset = xen_offset_in_page(mapping),
- .len = len * sizeof(u32),
+ .len = len * sizeof(*mapping),
.flags = GNTCOPY_source_gref
};
- if ((off + len > vif->hash.size) || copy_op.len > XEN_PAGE_SIZE)
+ if ((off + len < off) || (off + len > vif->hash.size) ||
+ len > XEN_PAGE_SIZE / sizeof(*mapping))
return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
+ copy_op.dest.u.gmfn = virt_to_gfn(mapping + off);
+ copy_op.dest.offset = xen_offset_in_page(mapping + off);
+
while (len-- != 0)
if (mapping[off++] >= vif->num_queues)
return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;