File 51f9f80d-fix-copying-bitmaps.patch of Package libvirt.11700
commit 51f9f80d350e633adf479c6a9b3c55f82ca9cbd4
Author: Allen, John <John.Allen@amd.com>
Date: Mon Apr 15 14:43:07 2019 +0000
Handle copying bitmaps to larger data buffers
If a bitmap of a shorter length than the data buffer is passed to
virBitmapToDataBuf, it will read off the end of the bitmap and copy junk
into the returned buffer. Add a check to only copy the length of the
bitmap to the buffer.
The problem can be observed after setting a vcpu affinity using the vcpupin
command on a system with a large number of cores:
# virsh vcpupin example_domain 0 0
# virsh vcpupin example_domain 0
VCPU CPU Affinity
---------------------------
0 0,192,197-198,202
Signed-off-by: John Allen <john.allen@amd.com>
Index: libvirt-5.1.0/src/util/virbitmap.c
===================================================================
--- libvirt-5.1.0.orig/src/util/virbitmap.c
+++ libvirt-5.1.0/src/util/virbitmap.c
@@ -824,11 +824,15 @@ virBitmapToDataBuf(virBitmapPtr bitmap,
unsigned char *bytes,
size_t len)
{
+ size_t nbytes = bitmap->map_len * (VIR_BITMAP_BITS_PER_UNIT / CHAR_BIT);
unsigned long *l;
size_t i, j;
memset(bytes, 0, len);
+ /* If bitmap and buffer differ in size, only fill to the smaller length */
+ len = MIN(len, nbytes);
+
/* htole64 is not provided by gnulib, so we do the conversion by hand */
l = bitmap->map;
for (i = j = 0; i < len; i++, j++) {