Commit Graph
1431 Commits
Author SHA1 Message Date
Andrew Cooper e21b2fa199 libxc: Fix out-of-memory error handling in xc_cpupool_getinfo()
Avoid freeing info then returning it to the caller.

This is XSA-88.

Coverity-ID: 1056192
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit d883c179a7)
2014-02-12 16:53:57 +00:00
Matthew Daley ac63ddd70a libxc: check blob size before proceeding in xc_dom_check_gzip
This is part of the fix to a security issue, XSA-55.

Signed-off-by: Matthew Daley <mattjd@gmail.com>
2013-06-14 16:45:41 +01:00
Ian Jackson 6eca85d5c1 libxc: range checks in xc_dom_p2m_host and _guest
These functions take guest pfns and look them up in the p2m.  They did
no range checking.

However, some callers, notably xc_dom_boot.c:setup_hypercall_page want
to pass untrusted guest-supplied value(s).  It is most convenient to
detect this here and return INVALID_MFN.

This is part of the fix to a security issue, XSA-55.

Changes from Xen 4.2 version of this patch:
* 4.2 lacks dom->rambase_pfn, so don't add/subtract/check it.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:41 +01:00
Ian Jackson a2986a7959 libxc: check return values from malloc
A sufficiently malformed input to libxc (such as a malformed input ELF
or other guest-controlled data) might cause one of libxc's malloc() to
fail.  In this case we need to make sure we don't dereference or do
pointer arithmetic on the result.

Search for all occurrences of \b(m|c|re)alloc in libxc, and all
functions which call them, and add appropriate error checking where
missing.

This includes the functions xc_dom_malloc*, which now print a message
when they fail so that callers don't have to do so.

The function xc_cpuid_to_str wasn't provided with a sane return value
and has a pretty strange API, which now becomes a little stranger.
There are no in-tree callers.

Changes in the Xen 4.2 version of this series:
* No need to fix code relating to ARM.
* No need to fix code relating to superpage support.
* Additionally fix `dom->p2m_host = xc_dom_malloc...' in xc_dom_ia64.c.

Changes in the Xen 4.1 version of this series:
* An additional check is needed in xc_flask.c:xc_flask_access.

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:41 +01:00
Ian Jackson 117a538dbe libxc: check failure of xc_dom_*_to_ptr, xc_map_foreign_range
The return values from xc_dom_*_to_ptr and xc_map_foreign_range are
sometimes dereferenced, or subjected to pointer arithmetic, without
checking whether the relevant function failed and returned NULL.

Add an appropriate error check at every call site.

Changes in the 4.2 backport of this series:
* Fix tools/libxc/xc_dom_x86.c:setup_pgtables_x86_32.
* Fix tools/libxc/xc_dom_ia64.c:start_info_ia64.
* Fix tools/libxc/ia64/xc_ia64_dom_fwloader.c:xc_dom_load_fw_kernel.

Conflicts in the 4.1 backport of this series:
* xc_dom_load_elf_kernel has less error handling in 4.1.
* the VM generation ID code is not in 4.1.

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:40 +01:00
Ian Jackson 40b76f1fb0 libxc: Add range checking to xc_dom_binloader
This is a simple binary image loader with its own metadata format.
However, it is too careless with image-supplied values.

Add the following checks:

 * That the image is bigger than the metadata table; otherwise the
   pointer arithmetic to calculate the metadata table location may
   yield undefined and dangerous values.

 * When clamping the end of the region to search, that we do not
   calculate pointers beyond the end of the image.  The C
   specification does not permit this and compilers are becoming ever
   more determined to miscompile code when they can "prove" various
   falsehoods based on assertions from the C spec.

 * That the supplied image is big enough for the text we are allegedly
   copying from it.  Otherwise we might have a read overrun and copy
   the results (perhaps a lot of secret data) into the guest.

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:40 +01:00
Ian Jackson 4a3a60d8ca libelf: abolish obsolete macros
Abolish ELF_PTRVAL_[CONST_]{CHAR,VOID}; change uses to elf_ptrval.
Abolish ELF_HANDLE_DECL_NONCONST; change uses to ELF_HANDLE_DECL.
Abolish ELF_OBSOLETE_VOIDP_CAST; simply remove all uses.

No functional change.  (Verified by diffing assembler output.)

This is part of the fix to a security issue, XSA-55.

Conflicts in the 4.1 backport:
 * elf_load_image is not in 4.1.
 * elf_note_numeric_array is not in 4.1.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2013-06-14 16:45:40 +01:00
Ian Jackson 968c039915 libelf: check loops for running away
Ensure that libelf does not have any loops which can run away
indefinitely even if the input is bogus.  (Grepped for \bfor, \bwhile
and \bgoto in libelf and xc_dom_*loader*.c.)

Changes needed:
 * elf_note_next uses the note's unchecked alleged length, which might
   wrap round.  If it does, return ELF_MAX_PTRVAL (0xfff..fff) instead,
   which will be beyond the end of the section and so terminate the
   caller's loop.
 * In various loops over section and program headers, check that the
   calculated header pointer is still within the image, and quit the
   loop if it isn't.

We have not changed loops which might, in principle, iterate over the
whole image - even if they might do so one byte at a time with a
nontrivial access check function in the middle.

This is part of the fix to a security issue, XSA-55.

Conflicts in Xen 4.1 version of the series:
* Trivial conflict due to elf_note_numeric_array not existing.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:40 +01:00
Ian Jackson 282188ea84 libxc: Introduce xc_bitops.h
Copy the one file tools/libxc/xc_bitops.h from xen.git#aa1355f9.
We will need this for the next patch, which calls for a bitmap in
libxc.

xc_bitops.h was introduced to unify various existing sets of bitmap
operations.  In this patch we backport only the introduction, not the
replacement of the other instances.  So we introduce another instance
Sorry :-/.

This is part of the fix to a security issue, XSA-55.

This patch is unique to the Xen 4.1 version of the XSA-55 series.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:40 +01:00
Ian Jackson 86e39ce58e libelf: use only unsigned integers
Signed integers have undesirable undefined behaviours on overflow.
Malicious compilers can turn apparently-correct code into code with
security vulnerabilities etc.

So use only unsigned integers.  Exceptions are booleans (which we have
already changed) and error codes.

We _do_ change all the chars which aren't fixed constants from our own
text segment, but not the char*s.  This is because it is safe to
access an arbitrary byte through a char*, but not necessarily safe to
convert an arbitrary value to a char.

As a consequence we need to compile libelf with -Wno-pointer-sign.

It is OK to change all the signed integers to unsigned because all the
inequalities in libelf are in contexts where we don't "expect"
negative numbers.

In libelf-dominfo.c:elf_xen_parse we rename a variable "rc" to
"more_notes" as it actually contains a note count derived from the
input image.  The "error" return value from elf_xen_parse_notes is
changed from -1 to ~0U.

grepping shows only one occurrence of "PRId" or "%d" or "%ld" in
libelf and xc_dom_elfloader.c (a "%d" which becomes "%u").

This is part of the fix to a security issue, XSA-55.

Conflicts in 4.1 series:
 * xc_dom_load_elf_kernel has no rc variable to change.
 * elf_load_image doesn't exist.

For those concerned about unintentional functional changes, the
following rune produces a version of the patch which is much smaller
and eliminates only non-functional changes:

 GIT_EXTERNAL_DIFF=.../unsigned-differ git-diff <before>..<after>

where <before> and <after> are git refs for the code before and after
this patch, and unsigned-differ is this shell script:

    #!/bin/bash
    set -e

    seddery () {
            perl -pe 's/\b(?:elf_errorstatus|elf_negerrnoval)\b/int/g'
    }

    path="$1"
    in="$2"
    out="$5"

    set +e
    diff -pu --label "$path~" <(seddery <"$in") --label "$path" <(seddery <"$out")
    rc=$?
    set -e
    if [ $rc = 1 ]; then rc=0; fi
    exit $rc

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:39 +01:00
Ian Jackson bd3dba9f43 libelf: use C99 bool for booleans
We want to remove uses of "int" because signed integers have
undesirable undefined behaviours on overflow.  Malicious compilers can
turn apparently-correct code into code with security vulnerabilities
etc.

In this patch we change all the booleans in libelf to C99 bool,
from <stdbool.h>.

For the one visible libelf boolean in libxc's public interface we
retain the use of int to avoid changing the ABI; libxc converts it to
a bool for consumption by libelf.

It is OK to change all values only ever used as booleans to _Bool
(bool) because conversion from any scalar type to a _Bool works the
same as the boolean test in if() or ?: and is always defined (C99
6.3.1.2).  But we do need to check that all these variables really are
only ever used that way.  (It is theoretically possible that the old
code truncated some 64-bit values to 32-bit ints which might become
zero depending on the value, which would mean a behavioural change in
this patch, but it seems implausible that treating 0x????????00000000
as false could have been intended.)

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:39 +01:00
Ian Jackson 44c74b1ed3 libelf: Make all callers call elf_check_broken
This arranges that if the new pointer reference error checking
tripped, we actually get a message about it.  In this patch these
messages do not change the actual return values from the various
functions: so pointer reference errors do not prevent loading.  This
is for fear that some existing kernels might cause the code to make
these wild references, which would then break, which is not a good
thing in a security patch.

In xen/arch/x86/domain_build.c we have to introduce an "out" label and
change all of the "return rc" beyond the relevant point into "goto
out".

This is part of the fix to a security issue, XSA-55.

Differences in 4.1 backport:
 * No xen/arch/arm.
 * There was less error handling in xen/arch/x86/domain_build.c
   so less need to change it.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:39 +01:00
Ian Jackson 9962d7ffcc libelf: Check pointer references in elf_is_elfbinary
elf_is_elfbinary didn't take a length parameter and could potentially
access out of range when provided with a very short image.

We only need to check the size is enough for the actual dereference in
elf_is_elfbinary; callers are just using it to check the magic number
and do their own checks (usually via the new elf_ptrval system) before
dereferencing other parts of the header.

This is part of the fix to a security issue, XSA-55.

Conflicts in 4.1 backport:
 * xen/arch/x86/bzimage.c in 4.1 doesn't use elf_is_elfbinary.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-14 16:45:38 +01:00
Ian Jackson 39923542bb libelf: check all pointer accesses
We change the ELF_PTRVAL and ELF_HANDLE types and associated macros:

 * PTRVAL becomes a uintptr_t, for which we provide a typedef
   elf_ptrval.  This means no arithmetic done on it can overflow so
   the compiler cannot do any malicious invalid pointer arithmetic
   "optimisations".  It also means that any places where we
   dereference one of these pointers without using the appropriate
   macros or functions become a compilation error.

   So we can be sure that we won't miss any memory accesses.

   All the PTRVAL variables were previously void* or char*, so
   the actual address calculations are unchanged.

 * ELF_HANDLE becomes a union, one half of which keeps the pointer
   value and the other half of which is just there to record the
   type.

   The new type is not a pointer type so there can be no address
   calculations on it whose meaning would change.  Every assignment or
   access has to go through one of our macros.

 * The distinction between const and non-const pointers and char*s
   and void*s in libelf goes away.  This was not important (and
   anyway libelf tended to cast away const in various places).

 * The fields elf->image and elf->dest are renamed.  That proves
   that we haven't missed any unchecked uses of these actual
   pointer values.

 * The caller may fill in elf->caller_xdest_base and _size to
   specify another range of memory which is safe for libelf to
   access, besides the input and output images.

 * When accesses fail due to being out of range, we mark the elf
   "broken".  This will be checked and used for diagnostics in
   a following patch.

   We do not check for write accesses to the input image.  This is
   because libelf actually does this in a number of places.  So we
   simply permit that.

 * Each caller of libelf which used to set dest now sets
   dest_base and dest_size.

 * In xc_dom_load_elf_symtab we provide a new actual-pointer
   value hdr_ptr which we get from mapping the guest's kernel
   area and use (checking carefully) as the caller_xdest area.

 * The STAR(h) macro in libelf-dominfo.c now uses elf_access_unsigned.

 * elf-init uses the new elf_uval_3264 accessor to access the 32-bit
   fields, rather than an unchecked field access (ie, unchecked
   pointer access).

 * elf_uval has been reworked to use elf_uval_3264.  Both of these
   macros are essentially new in this patch (although they are derived
   from the old elf_uval) and need careful review.

 * ELF_ADVANCE_DEST is now safe in the sense that you can use it to
   chop parts off the front of the dest area but if you chop more than
   is available, the dest area is simply set to be empty, preventing
   future accesses.

 * We introduce some #defines for memcpy, memset, memmove and strcpy:
    - We provide elf_memcpy_safe and elf_memset_safe which take
      PTRVALs and do checking on the supplied pointers.
    - Users inside libelf must all be changed to either
      elf_mem*_unchecked (which are just like mem*), or
      elf_mem*_safe (which take PTRVALs) and are checked.  Any
      unchanged call sites become compilation errors.

 * We do _not_ at this time fix elf_access_unsigned so that it doesn't
   make unaligned accesses.  We hope that unaligned accesses are OK on
   every supported architecture.  But it does check the supplied
   pointer for validity.

This is part of the fix to a security issue, XSA-55.

Additional change in 4.1 backport:
* ELF_PRPTRVAL needs to be defined oddly on 4.1 and earlier because
  Xen's headers provide no definitions of uintptr_t or PRIuPTR.

Conflicts:
* Callers of elf_load_binary don't check its return value in 4.1.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2013-06-14 16:45:38 +01:00
Ian Jackson de49d6e83c libelf: introduce macros for memory access and pointer handling
We introduce a collection of macros which abstract away all the
pointer arithmetic and dereferences used for accessing the input ELF
and the output area(s).  We use the new macros everywhere.

For now, these macros are semantically identical to the code they
replace, so this patch has no functional change.

elf_is_elfbinary is an exception: since it doesn't take an elf*, we
need to handle it differently.  In a future patch we will change it to
take, and check, a length parameter.  For now we just mark it with a
fixme.

Nontrivial differences in the 4.1 backport:
 * We need to provide our own elf_uintptr_t since Xen doesn't.
 * We see some additional differences in our verification diff.
 * The "function-filter" needs to massage additional symbol names.
Conflicts:
 * In xc_dom_load_elf_symtab the old code used
     *(Elf64_Word*)(&shdr->e64.sh_name) and the new Elf32_Word
   but in fact the type in the struct has changed too so the
   new code using elf_store_field is still correct.
 * loadelfimage, elf_load_image etc. don't exist and are done
   directly with memcpy/memset; patch adjusted appropriately.
 * elf_note_numeric_array doesn't exist in 4.1.

That this patch has no functional change can be verified as follows:

  0. Copy the scripts "comparison-generate" and "function-filter"
     out of this commit message.
  1. Check out the tree before this patch.
  2. Run the script ../comparison-generate .... ../before
  3. Check out the tree after this patch.
  4. Run the script ../comparison-generate .... ../after
  5. diff --exclude=\*.[soi] -ruN before/ after/ |less

Expect these differences:
  * stubdom/zlib-x86_64/ztest*.s2
      The filename of this test file apparently contains the pid.
  * stubdom/grub/kexec.s2:
      Large differences following ".section .debug_info" (which
      the 4.1 build system erroneously fails to suppress).
  * tools/libxc/xc_domain_restore.s2 (64-bit build):
      One trivial code gen difference with no semantic import.
  * xen/common/version.s2
      The xen build timestamp appears in two diff hunks.

Verification that this is all that's needed:
  In a completely built xen.git,
     find * -name .*.d -type f | xargs grep -l libelf\.h
  Expect results in:
     xen/arch/x86:            Checked above.
     tools/libxc:             Checked above.
     tools/xcutils/readnotes: Checked above.
     tools/xenstore:          Checked above.
     xen/common/libelf:
       This is the build for the hypervisor; checked in B above.
     stubdom:
       We have one stubdom which reads ELFs using our libelf,
       pvgrub, which is checked above.

I have not done this verification for ARM.

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

-8<- comparison-generate -8<-
 #!/bin/bash
 # usage:
 #  cd xen.git
 #  .../comparison-generate OUR-CONFIG BUILD-RUNE-PREFIX ../before|../after
 # eg:
 #  .../comparison-generate ~/work/.config 'schroot -pc64 --' ../before
 set -ex

 test $# = 3 || need-exactly-three-arguments

 our_config=$1
 build_rune_prefix=$2
 result_dir=$3

 git clean -x -d -f

 cp "$our_config" .

 cat <<END >>.config
         debug_symbols=n
         CFLAGS += -save-temps
 END

 perl -i~ -pe 's/ -g / -g0 / if m/^CFLAGS/' xen/Rules.mk

 if [ -f ./configure ]; then
         $build_rune_prefix ./configure
 fi

 $build_rune_prefix make -C xen
 $build_rune_prefix make -C tools/include
 $build_rune_prefix make -C stubdom grub
 $build_rune_prefix make -C tools/libxc
 $build_rune_prefix make -C tools/xenstore
 $build_rune_prefix make -C tools/xcutils

 rm -rf "$result_dir"
 mkdir "$result_dir"

 set +x
 for f in `find xen tools stubdom -name \*.[soi]`; do
         mkdir -p "$result_dir"/`dirname $f`
         cp $f "$result_dir"/${f}
         case $f in
         *.s)
                 ../function-filter <$f >"$result_dir"/${f}2
                 ;;
         esac
 done

 echo ok.
-8<-

-8<- function-filter -8<-
 #!/usr/bin/perl -w
 # function-filter
 # script for massaging gcc-generated labels to be consistent
 use strict;
 our @lines;
 my $sedderybody = "sub seddery () {\n";
 while (<>) {
     push @lines, $_;
     if (m/^(__FUNCTION__|__func__|_ctx|note_desc|types|last_order|memflags|mutex|d\d_cpu_last|write_count|wall_last|__PRETTY_FUNCTION__)\.(\d+)\:/ ||
         m/^\s+\.local\s+(_ctx|write_count|d\d_cpu_last|wall_last|mutex)\.(\d+)\s*$/) {
         $sedderybody .= "    s/\\b$1\\.$2\\b/__XSA55MANGLED__$1.$./g;\n";
     }
 }
 $sedderybody .= "}\n1;\n";
 eval $sedderybody or die $@;
 foreach (@lines) {
     seddery();
     print or die $!;
 }
-8<-
2013-06-14 16:45:37 +01:00
Ian Jackson 4d3339de1f libelf/xc_dom_load_elf_symtab: Do not use "syms" uninitialised
xc_dom_load_elf_symtab (with load==0) calls elf_round_up, but it
mistakenly used the uninitialised variable "syms" when calculating
dom->bsd_symtab_start.  This should be a reference to "elf".

This change might have the effect of rounding the value differently.
Previously if the uninitialised value (a single byte on the stack) was
ELFCLASS64 (ie, 2), the alignment would be to 8 bytes, otherwise to 4.

However, the value is calculated from dom->kernel_seg.vend so this
could only make a difference if that value wasn't already aligned to 8
bytes.

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2013-06-14 16:45:37 +01:00
Ian Jackson f7fb94409c libxc: Fix range checking in xc_dom_pfn_to_ptr etc.
* Ensure that xc_dom_pfn_to_ptr (when called with count==0) does not
  return a previously-allocated block which is entirely before the
  requested pfn (!)

* Provide a version of xc_dom_pfn_to_ptr, xc_dom_pfn_to_ptr_retcount,
  which provides the length of the mapped region via an out parameter.

* Change xc_dom_vaddr_to_ptr to always provide the length of the
  mapped region and change the call site in xc_dom_binloader.c to
  check it.  The call site in xc_dom_load_elf_symtab will be corrected
  in a forthcoming patch, and for now ignores the returned length.

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

v5: This patch is new in v5 of the series.
2013-06-14 16:45:36 +01:00
Ian Jackson bbf40e6b6d libxc: introduce xc_dom_seg_to_ptr_pages
Provide a version of xc_dom_seg_to_ptr which returns the number of
guest pages it has actually mapped.  This is useful for callers who
want to do range checking; we will use this later in this series.

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-14 16:45:36 +01:00
Ian Jackson 64a0206c45 libelf: abolish libelf-relocate.c
This file is not actually used.  It's not built in Xen's instance of
libelf; in libxc's it's built but nothing in it is called.  Do not
compile it in libxc, and delete it.

This reduces the amount of work we need to do in forthcoming patches
to libelf (particularly since as libelf-relocate.c is not used it is
probably full of bugs).

This is part of the fix to a security issue, XSA-55.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2013-06-14 16:45:36 +01:00
Jan Beulich 22d89f4a09 fix XSA-46 regression with xend/xm
The hypervisor side changes for XSA-46 require the tool stack to now
always map the guest pIRQ before granting access permission to the
underlying host IRQ (GSI). This in particular requires that pciif.py
no longer can skip this step (assuming qemu would do it) for HVM
guests.

This in turn exposes, however, an inconsistency between xend and qemu:
The former wants to always establish 1:1 mappings between pIRQ and host
IRQ (for non-MSI only of course), while the latter always wants to
allocate an arbitrary mapping. Since the whole tool stack obviously
should always agree on the mapping model, make libxc enforce the 1:1
mapping as the more natural one (as well as being the one that allows
for easier debugging, since there no need to find out the extra
mapping). Users of libxc that want to establish a particular (rather
than an allocated) mapping are still free to do so, as well as tool
stacks not based on libxc wanting to implement an allocation based
model (which is why it's not the hypervisor that's being changed to
enforce either model).

Since libxl, like xend, already uses a 1:1 model, it's unaffected by
the libxc change (and it being unaffected by the original hypervisor
side changes is - afaict - simply due to qemu getting spawned at a
later point in time compared to the xend event flow).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Andreas Falck <falck.andreas.lists@gmail.com> (on 4.1)
Tested-by: Gordan Bobic <gordan@bobich.net> (on 4.2)
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 934a5253d9
master date: 2013-05-21 11:32:34 +0200
2013-05-23 15:16:44 +02:00
Ian Jackson 5e73e3548c Add DomU xz kernel decompression
Signed-off-by: Jan Beulich <jbeulich@novell.com>

xen-unstable changeset: 4afea3d653
xen-unstable date: Wed Mar 9 16:19:36 2011 +0000
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

[ This is byte-for-byte identical to Bastian Blank's backport of the
  same changeset to xen-4.1, as found in Debian xen_4.1.4-2.*
  patch debian/patches/upstream-23002:eb64b8f8eebb  -iwj ]
2013-03-15 18:19:14 +00:00
Michael Young bdce365321 tools: Fix memset(&p,0,sizeof(p)) idiom in several places.
gcc 4.8 identifies several places where code of the form memset(x, 0,
sizeof(x)); is used incorrectly, meaning that less memory is set to
zero than required.

Signed-off-by: Michael Young <m.a.young@durham.ac.uk>
Committed-by: Keir Fraser <keir@xen.org>
(cherry picked from commit d119301b58)
2013-02-28 11:48:29 +00:00
Ian Jackson 7ce4c76597 libxc: builder: limit maximum size of kernel/ramdisk.
Allowing user supplied kernels of arbitrary sizes, especially during
decompression, can swallow up dom0 memory leading to either virtual
address space exhaustion in the builder process or allocation
failures/OOM killing of both toolstack and unrelated processes.

We disable these checks when building in a stub domain for pvgrub
since this uses the guest's own memory and is isolated.

Decompression of gzip compressed kernels and ramdisks has been safe
since 14954:58205257517d (Xen 3.1.0 onwards).

This is XSA-25 / CVE-2012-4544.

Also make explicit checks for buffer overflows in various
decompression routines. These were already ruled out due to other
properties of the code but check them as a belt-and-braces measure.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ Includes 25589:60f09d1ab1fe for CVE-2012-2625 ]
2012-10-26 16:10:04 +01:00
Jan Beulich ffeab3a855 x86/PoD: prevent guest from being destroyed upon early access to its memory
When an external agent (e.g. a monitoring daemon) happens to access the
memory of a PoD guest prior to setting the PoD target, that access must
fail for there not being any page in the PoD cache, and only the space
above the low 2Mb gets scanned for victim pages (while only the low 2Mb
got real pages populated so far).

To accomodate for this
- set the PoD target first
- do all physmap population in PoD mode (i.e. not just large [2Mb or
  1Gb] pages)
- slightly lift the restrictions enforced by p2m_pod_set_mem_target()
  to accomodate for the changed tools behavior

Tested-by: Jürgen Groß <juergen.gross@ts.fujitsu.com>
           (in a 4.0.x based incarnation)
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
xen-unstable changeset: 25754:be8ae5439a88
xen-unstable date: Thu Aug 16 08:14:11 UTC 2012
2012-09-20 10:46:23 +02:00
Liu, Jinsong 866f66eda1 X86: Disable PCID/INVPCID for pv
This patch disable PCID/INVPCID for pv.

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
xen-unstable changeset: 24360:d313582d4fa2
xen-unstable date: Tue Dec  6 11:28:04 UTC 2011
2012-09-04 14:40:53 +02:00
David Vrabel 425917b9d0 libxc: remove tests of alloca() return value
alloca() does not return NULL on an allocation failure on Linux so
remove the unneccessary tests from this Linux-specific code.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Santosh Jodh <santosh.jodh@citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
xen-unstable changeset:   24832:9cc7961d8f5c
xen-unstable date:        Mon Feb 20 17:31:49 2012 +0000
2012-03-07 09:39:45 +00:00
Santosh Jodh 45db68b57f libxc: Replace malloc with alloca in hot path
Replace malloc with alloc in hot paths for improved performance.

Signed-off-by: Santosh Jodh <santosh.jodh@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
xen-unstable changeset:   24709:8ba7ae0b070b
xen-unstable date:        Tue Feb 07 18:46:50 2012 +0000
2012-03-07 09:39:10 +00:00
Keir Fraser 4b8ccb98a5 tools/libxc: Fix x86_32 build breakage in previous changeset.
Signed-off-by: Keir Fraser <keir@xen.org>
xen-unstable changeset:   24345:491c3ebf1d37
xen-unstable date:        Fri Dec 02 08:40:02 2011 -0800


tools/x86_64: Fix cpuid() inline asm to not clobber stack's red zone

Pushing stuff onto the stack on x86-64 when we do not specify
-mno-red-zone is unsafe. Since the complicated asm is due to register
pressure on i386, we simply implement an all-new simpler alternative
for x86-64.

Signed-off-by: Keir Fraser <keir@xen.org>
Acked-by: Jan Beulich <jbeulich@novell.com>
xen-unstable changeset:   24344:72f4e4cb7440
xen-unstable date:        Fri Dec 02 06:31:14 2011 -0800
2011-12-06 10:52:25 +00:00
Paul Durrant 685056bba7 hvm/viridian: Ditch the extra assertions/warnings for non-viridian guests.
Consensus is they are over-aggressive.

Signed-off-by: Keir Fraser <keir@xen.org>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
xen-unstable changeset:   24230:96bbdc894224
xen-unstable date:        Fri Nov 25 15:48:03 2011 +0000


Fix save/restore for HVM domains with viridian=1

xc_domain_save/restore currently pay no attention to
HVM_PARAM_VIRIDIAN which results in an HVM domain running a recent
version on Windows (post-Vista) locking up on a domain restore due to
EOIs (done via a viridian MSR write) being silently dropped.  This
patch adds an extra save entry for the viridian parameter and also
adds code in the viridian kernel module to catch attempted use of
viridian functionality when the HVM parameter has not been set.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Committed-by: Keir Fraser <keir@xen.org>
xen-unstable changeset:   24229:373bd877cac3
xen-unstable date:        Fri Nov 25 15:30:41 2011 +0000
2011-12-06 10:51:20 +00:00
Keir Fraser 7297daddfa build: Make XEN_ROOT an absolute path.
Otherwise make can search the path relative to certain standard paths
such as /usr/include (e.g., the line '-include $(XEN_ROOT)/.config' in
Config.mk suffers from this).

Signed-off-by: Keir Fraser <keir@xen.org>

xen-unstable changeset: 23049:ff3b7749008b
Backport-requested-by: Allen M Kay <allen.m.kay@intel.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-10-06 19:47:14 +01:00
Ian Campbell 04aa57c1d0 libxc: remove obsolete comment.
Seems to predate Xen 3.0...

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
xen-unstable changeset:   23707:9afeab10a65d
xen-unstable date:        Sat Jul 16 09:18:45 2011 +0100
2011-07-20 15:24:09 +01:00
David Vrabel b877dbb2df xen/libxc: set CPUID topology leaf as unsupported for PV guests
The result of a CPUID Extended Topology Enumeration leaf for PV guests
is invalid as the level in ECX is ignored.  This can cause some guests
to loop endlessly when trying to enumerate the topology.

Since the physical topology isn't useful to PV guests set the topology
leaf as unsupported.

Guests affected include Linux kernels prior 2.6.32 where a workaround
was applied ("xen: mask extended topology info in cpu",
82d6469916c6fcfa345636a49004c9d1753905d1).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen-unstable changeset:   23700:867bb675b57b
xen-unstable date:        Sat Jul 16 09:05:45 2011 +0100
2011-07-16 09:33:07 +01:00
Keir Fraser 08a523f941 x86: Backport CPUID feature passthroughs from xen-unstable
Enable RDWRGSFS feature support for HVM guests

Write/read FS/GS base instructions enable user level code to
read/write FS & GS segment base registers for thread local storage.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
xen-unstable changeset:   23539:8c75f35d55f6
xen-unstable date:        Wed Jun 15 16:06:48 2011 +0100

x86: Pass through ERMS CPUID feature for HVM and PV guests

This patch exposes ERMS feature to HVM and PV guests.

The REP MOVSB/STOSB instruction can enhance fast strings attempts to
move as much of the data with larger size load/stores as possible.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
xen-unstable changeset:   23516:f4a47275aebf
xen-unstable date:        Tue Jun 14 13:13:18 2011 +0100

x86/hvm: Make DRNG feature visible in CPUID

This patch exposes DRNG feature to HVM guests.

The RDRAND instruction can provide software with sequences of
random numbers generated from white noise.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
xen-unstable changeset:   23510:864a3dd1d9b4
xen-unstable date:        Tue Jun 14 12:44:48 2011 +0100
2011-06-23 11:59:45 +01:00
Keir Fraser a82874185a x86/hvm: add SMEP support to HVM guest
Intel new CPU supports SMEP (Supervisor Mode Execution
Protection). SMEP
prevents software operating with CPL < 3 (supervisor mode) from
fetching
instructions from any linear address with a valid translation for
which the U/S
flag (bit 2) is 1 in every paging-structure entry controlling the
translation
for the linear address.

This patch adds SMEP support to HVM guest.

Signed-off-by: Yang Wei <wei.y.yang@intel.com>
Signed-off-by: Shan Haitao <haitao.shan@intel.com>
Signed-off-by: Li Xin <xin.li@intel.com>
Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>
xen-unstable changeset:   23504:c34604d5a293
xen-unstable date:        Mon Jun 06 13:46:48 2011 +0100
2011-06-23 11:54:53 +01:00
Keir Fraser 8e3850ae16 x86: Hide CPUID leaf 7 from PV guests.
Except for the whitelisted FSGSBASE feature.

Signed-off-by: Keir Fraser <keir@xen.org>
xen-unstable changeset:   23461:5839e797a130
xen-unstable date:        Thu Jun 02 14:39:50 2011 +0100
2011-06-02 14:45:00 +01:00
Markus Gross 59a57952bd libxc: obtain correct length of p2m during core dumping
while implementing core dumping functionality for the libxl driver
of libvirt, I discovered an issue with mapping pages of a pv guest.

After dumping the core of a pv guest the domain was not cleared up
properly and some pages were not unmapped. This issue is similar
to the one reported here:
http://lists.xensource.com/archives/html/xen-devel/2011-05/msg01314.html

In xc_domain_dumpcore_via_callback in the file xc_core.c the function
xc_core_arch_map_p2m is called to map P2M_FL_ENTRIES pages to the
variable p2m.
But to unmap the pages later, the dinfo->p2m_size has to be set
accordingly.
This was not done, instead a variable named p2m_size was set.
This way P2M_FL_ENTRIES was always zero and the pages were left
mapped.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
xen-unstable changeset:   23374:8bd7b5e98f2a
xen-unstable date:        Tue May 24 15:00:16 2011 +0100
2011-05-28 09:09:40 +01:00
Jim Fehlig 8f751ee205 libxc: after saving, unmap correct amount for live_m2p
With some help from Olaf, I've finally got to the bottom of an issue I
came across while trying to implement save/restore in the libvirt
libxenlight driver.  After issuing the save operation, the saved
domain was not being cleaned up properly and left in this state from
xl's perspective

xen33:# xl list
Name                   ID   Mem VCPUs      State   Time(s)
Domain-0                0  6821     8     r-----     122.5
(null)                  2     2     2     --pssd      10.8

Checking the libvirtd /proc/$pid/maps I found this

7f3798984000-7f3798b86000 r--s 00002000 00:03 4026532097
/proc/xen/privcmd

So not all all pages belonging to the domain were unmapped from
libvirtd.  In tools/libxc/xc_domain_save.c we found that
P2M_FL_ENTRIES were being mapped but only P2M_FLL_ENTRIES were being
unmapped.  The attached patch changes the unmapping to use the same
P2M_FL_ENTRIES macro.  I'm not too familiar with this code though so
posting here for review.

I suspect this was not noticed before since most (all?) processes
doing save terminate after the save and are not long-running like
libvirtd.

Ian Campbell writes:
> Looks like I introduced this in 18558:ccf0205255e1, sorry!
>
> I guess it is also wrong in the error path out of map_and_save_p2m_table
> and so we also need [another hunk].

This change should be backported to relevant earlier trees. -iwj

From: Jim Fehlig <jfehlig@novell.com>
From: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
xen-unstable changeset:   23373:171007b4e2c4
xen-unstable date:        Tue May 24 14:50:00 2011 +0100
2011-05-28 09:08:21 +01:00
Ian Jackson 0416d74e9e libxc: [CVE-2011-1583] pv kernel image validation
The functions which interpret the kernel image supplied for a
paravirtualised guest, and decompress it into memory when booting the
domain, are incautious.  Specifically:

 (i) Integer overflow in the decompression loop memory allocator might
    result in overrunning the buffer used for the decompressed image;
 (ii) Integer overflows and lack of checking of certain length fields
    can result in the loader reading its own address space beyond the
    size of the supplied kernel image file.
 (iii) Lack of error checking in the decompression loop can lead to an
    infinite loop.

This patch fixes these problems.

CVE-2011-1583.

Signed-off-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-05-09 15:04:01 +01:00
Keir Fraser e9a24e2228 libxc: Fill in XSAVE-related CPUID leaves for PV guests.
Signed-off-by: Keir Fraser <keir@xen.org>
xen-unstable changeset:   23248:16aac67e948c
xen-unstable date:        Mon Apr 25 15:27:56 2011 +0100
2011-04-25 15:28:33 +01:00
Gianni Tedesco 416c557581 libxc: set all VCPU's online by default in HVM info table
This sets a saner default for the cpu-online-map by setting all bits
to 1. The default assumption ought to be that nr-vcpus ==
nr-vcpus-at-start. If that is not true, then the toolstack must modify
the bitmap, but if it is true, the toolstack oughtn't need to do
anything further.

Signed-off-by: Gianni Tedesco <gianni.tedesco@citrix.com>
xen-unstable changeset:   23179:2b66b83b19b6
xen-unstable date:        Thu Apr 07 12:13:58 2011 +0100
2011-04-07 15:26:58 +01:00
Ian Jackson 1153faff43 Merge 2011-03-03 18:52:09 +00:00
Keir Fraser c7f3f82a65 x86, libxc: Fix xc_translate_foreign_address() for PV guests of
different bitness than dom0 (32-bit vs 64-bit).

Original patch by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Keir Fraser <keir@xen.org>
2011-03-03 17:46:44 +00:00
George Dunlap aa6e4a53f6 libxc: Missed one when replacing read_exact with RDEXACT macro
This corrects an error in 21488:dd6bbdc42033.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-03-03 17:24:27 +00:00
Shriram Rajagopalan dc55dcd8f1 libxc: fix incorrect scanning of pfn array in pagebuf during migration
xc_domain_restore.c:apply_batch function makes two passes over the pfn_types
array in pagebuf to allocate the needed MFNs. The curbatch parameter to this
function specifies the array offset in pfn_types, from where the current scan
should begin. But this variable is not taken into account (index always starts
at 0) during the two passes. While this [bug] does not manifest itsef during
save/restore or live migration, under Remus, xc_domain_restore fails due to
corrupt guest page tables.

(This appears to have been broken by 21588:6c3d8aec202d which reverted
two changesets from before Remus support was added and hence
reintroduced some none-Remus compatible bits.)

Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-03-03 16:55:27 +00:00
George Dunlap c15cad7df6 libxc: Handle failed xc_get_hvm_param in domain save
The domain save code will read an HVM param, and if it's not zero,
make an entry for it.  However, if the hypercall fails for any reason,
the data may not be written, and the value for the previous parameter
may be written in the save file as the parameter that failed.

Initialize the value to zero before each hypercall, so that in case of
a failure, no value will be written.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-02-25 17:26:18 +00:00
KUWAMURA Shin'ya d721a18a0d [IA64] fix missing header: asm/fpswa.h
This patch fixes the following error in recent kernel:
  ia64/asm/dom_fw_common.h:47:23: error: asm/fpswa.h: No such file or
  directory

Signed-off-by: KUWAMURA Shin'ya <kuwa@jp.fujitsu.com>
2011-02-18 10:21:19 +00:00
Ian Jackson a14b0eb584 libxc: increase lzma max memory constant to 128Mby
According to lzma's configure.ac (!) the minimum memory limit to cope
with arbitrary input is 128Mby (!)

This is obviously an unreasonable amount of memory for this kind of
task, but we need to increase the constant limit for it not to
randomly fail.  So do so.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-02-11 17:49:13 +00:00
Ian Campbell 04d1f61a1f libxc: maintain a small, per-handle, cache of hypercall buffer memory
Constantly m(un)locking memory can have significant overhead on
systems with large numbers of CPUs. This was previously fixed by
20841:fbe8f32fa257 but this was dropped during the transition to
hypercall buffers.

Introduce a small cache of single page hypercall buffer allocations
which can be resused to avoid this overhead.

Add some statistics tracking to the hypercall buffer allocations.

The cache size of 4 was chosen based on these statistics since they
indicated that 2 pages was sufficient to satisfy all concurrent single
page hypercall buffer allocations seen during "xl create", "xl
shutdown" and "xl destroy" of both a PV and HVM guest therefore 4
pages should cover the majority of important cases.

This fixes http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=1719.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reported-by: Zheng, Shaohui <shaohui.zheng@intel.com>
Tested-by: Haitao Shan <maillists.shan@gmail.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-02-01 19:26:36 +00:00
Ian Jackson 9f187767c5 libxc: Do not use dom0 physmem as parameter to lzma decoder
It's not clear why a userspace lzma decode would want to use that
particular value, what bearing it has on anything or why it would
assume it could use 1/3 of the total RAM in the system (potentially
quite a large amount of RAM) as opposed to any other limit number.

Instead, hardcode 32Mby.

This reverts 22830:c80960244942, removes the xc_get_physmem/physmem
function entirely, and replaces the expression at the call site with a
fixed constant.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Cc: Christoph Egger <Christoph.Egger@amd.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-01-28 19:37:49 +00:00
Shan Haitao 4df98b33c2 tools/libxc, hvm: Fix 1G page allocation algorithm
Currently, cur_pages (which is used as index into page_array for
fetching gfns) is used to judge whether it is proper here to allocated
1G pages. However, cur_pages == page_array[cur_pages] only holds true
when it is below 4G. When it is above 4G, page_array[cur_pages] -
cur_pages = 256M.
As a result, when guest has 10G memory, 8 1G-pages are allocated. But
only 2 of them have their corresponding gfns 1G aligned. The other 6
are forced to split to 2M pages, as their starting gfns are 4G+256M,
5G+256M .................

Inside the patch, true gfns are used instead of cur_pages to fix this
issue.

Signed-off-by: Shan Haitao <haitao.shan@intel.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
2011-01-28 11:08:49 +00:00