0a7476
From 806c01fea005e3887ad74efa3ecbab8294c0ddca Mon Sep 17 00:00:00 2001
0a7476
Message-Id: <806c01fea005e3887ad74efa3ecbab8294c0ddca@dist-git>
0a7476
From: "Allen, John" <John.Allen@amd.com>
0a7476
Date: Fri, 26 Apr 2019 15:12:01 +0200
0a7476
Subject: [PATCH] Handle copying bitmaps to larger data buffers
0a7476
0a7476
If a bitmap of a shorter length than the data buffer is passed to
0a7476
virBitmapToDataBuf, it will read off the end of the bitmap and copy junk
0a7476
into the returned buffer. Add a check to only copy the length of the
0a7476
bitmap to the buffer.
0a7476
0a7476
The problem can be observed after setting a vcpu affinity using the vcpupin
0a7476
command on a system with a large number of cores:
0a7476
  # virsh vcpupin example_domain 0 0
0a7476
  # virsh vcpupin example_domain 0
0a7476
     VCPU   CPU Affinity
0a7476
    ---------------------------
0a7476
     0      0,192,197-198,202
0a7476
0a7476
Signed-off-by: John Allen <john.allen@amd.com>
0a7476
(cherry picked from commit 51f9f80d350e633adf479c6a9b3c55f82ca9cbd4)
0a7476
0a7476
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1703159
0a7476
0a7476
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
0a7476
Message-Id: <8c72d73f39288e0a38d72481e771d1df53d593a3.1556284274.git.phrdina@redhat.com>
0a7476
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
0a7476
---
0a7476
 src/util/virbitmap.c | 4 ++++
0a7476
 1 file changed, 4 insertions(+)
0a7476
0a7476
diff --git a/src/util/virbitmap.c b/src/util/virbitmap.c
0a7476
index 0cc5292d8c..0bc0d068bb 100644
0a7476
--- a/src/util/virbitmap.c
0a7476
+++ b/src/util/virbitmap.c
0a7476
@@ -832,11 +832,15 @@ virBitmapToDataBuf(virBitmapPtr bitmap,
0a7476
                    unsigned char *bytes,
0a7476
                    size_t len)
0a7476
 {
0a7476
+    size_t nbytes = bitmap->map_len * (VIR_BITMAP_BITS_PER_UNIT / CHAR_BIT);
0a7476
     unsigned long *l;
0a7476
     size_t i, j;
0a7476
 
0a7476
     memset(bytes, 0, len);
0a7476
 
0a7476
+    /* If bitmap and buffer differ in size, only fill to the smaller length */
0a7476
+    len = MIN(len, nbytes);
0a7476
+
0a7476
     /* htole64 is not provided by gnulib, so we do the conversion by hand */
0a7476
     l = bitmap->map;
0a7476
     for (i = j = 0; i < len; i++, j++) {
0a7476
-- 
0a7476
2.21.0
0a7476