xen/xsa155-qemuu-qdisk-double-access.patch
Charles Arnold 8292994238 - bsc#960093 - VUL-0: CVE-2015-8615: xen: x86: unintentional
logging upon guest changing callback method (XSA-169)
  5677f350-x86-make-debug-output-consistent-in-hvm_set_callback_via.patch

- bsc#959387 - VUL-0: CVE-2015-8568 CVE-2015-8567: xen: qemu: net:
  vmxnet3: host memory leakage
  CVE-2015-8568-qemuu-net-vmxnet3-avoid-memory-leakage-in-activate_device.patch

- bsc#957988 - VUL-0: CVE-2015-8550: xen: paravirtualized drivers
  incautious about shared memory contents (XSA-155)
  xsa155-xen-0001-xen-Add-RING_COPY_REQUEST.patch
  xsa155-xen-0002-blktap2-Use-RING_COPY_REQUEST.patch
  xsa155-xen-0003-libvchan-Read-prod-cons-only-once.patch
  xsa155-qemuu-qdisk-double-access.patch
  xsa155-qemut-qdisk-double-access.patch
  xsa155-qemuu-xenfb.patch
  xsa155-qemut-xenfb.patch
- bsc#959006 - VUL-0: CVE-2015-8558: xen: qemu: usb: infinite loop
  in ehci_advance_state results in DoS
  CVE-2015-8558-qemuu-usb-infinite-loop-in-ehci_advance_state-results-in-DoS.patch
- bsc#958918 - VUL-0: CVE-2015-7549: xen: qemu pci: null pointer
  dereference issue
  CVE-2015-7549-qemuu-pci-null-pointer-dereference-issue.patch
- bsc#958493 - VUL-0: CVE-2015-8504: xen: qemu: ui: vnc: avoid
  floating point exception
  CVE-2015-8504-qemuu-vnc-avoid-floating-point-exception.patch
  CVE-2015-8504-qemut-vnc-avoid-floating-point-exception.patch
- bsc#958007 - VUL-0: CVE-2015-8554: xen: qemu-dm buffer overrun in
  MSI-X handling (XSA-164)
  xsa164.patch

OBS-URL: https://build.opensuse.org/package/show/Virtualization/xen?expand=0&rev=393
2016-01-04 22:25:00 +00:00

44 lines
1.4 KiB
Diff

xen/blkif: Avoid double access to src->nr_segments
src is stored in shared memory and src->nr_segments is dereferenced
twice at the end of the function. If a compiler decides to compile this
into two separate memory accesses then the size limitation could be
bypassed.
Fix it by removing the double access to src->nr_segments.
This is part of XSA-155.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Index: xen-4.6.0-testing/tools/qemu-xen-dir-remote/hw/block/xen_blkif.h
===================================================================
--- xen-4.6.0-testing.orig/tools/qemu-xen-dir-remote/hw/block/xen_blkif.h
+++ xen-4.6.0-testing/tools/qemu-xen-dir-remote/hw/block/xen_blkif.h
@@ -85,8 +85,10 @@ static inline void blkif_get_x86_32_req(
d->nr_sectors = s->nr_sectors;
return;
}
- if (n > src->nr_segments)
- n = src->nr_segments;
+ /* prevent the compiler from optimizing the code and using src->nr_segments instead */
+ barrier();
+ if (n > dst->nr_segments)
+ n = dst->nr_segments;
for (i = 0; i < n; i++)
dst->seg[i] = src->seg[i];
}
@@ -106,8 +108,10 @@ static inline void blkif_get_x86_64_req(
d->nr_sectors = s->nr_sectors;
return;
}
- if (n > src->nr_segments)
- n = src->nr_segments;
+ /* prevent the compiler from optimizing the code and using src->nr_segments instead */
+ barrier();
+ if (n > dst->nr_segments)
+ n = dst->nr_segments;
for (i = 0; i < n; i++)
dst->seg[i] = src->seg[i];
}