Commit Graph
27167 Commits
Author SHA1 Message Date
Ian Jackson 8ee5e399c1 QEMU_TAG update 2013-06-17 17:41:25 +01:00
Jan Beulich 7a89f62ddd AMD IOMMU: make interrupt work again
Commit 899110e3 ("AMD IOMMU: include IOMMU interrupt information in 'M'
debug key output") made the AMD IOMMU MSI setup code use more of the
generic MSI setup code (as other than for VT-d this is an ordinary MSI-
capable PCI device), but failed to notice that till now interrupt setup
there _required_ the subsequent affinity setup to be done, as that was
the only point where the MSI message would get written. The generic MSI
affinity setting routine, however, does only an incremental change,
i.e. relies on this setup to have been done before.

In order to not make the code even more clumsy, introduce a new low
level helper routine __setup_msi_irq(), thus eliminating the need for
the AMD IOMMU code to directly fiddle with the IRQ descriptor.

Reported-by: Suravee Suthikulanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Acked-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
2013-06-17 10:30:57 +02:00
Ian Campbell b03165b4ed xen: arm: fix build after libelf changes.
ed65808a8ed4 "libelf: check all pointer accesses" caused:
    kernel.c: In function 'kernel_elf_load':
    kernel.c:162:18: error: 'struct elf_binary' has no member named 'dest'
    make[4]: *** [kernel.o] Error 1

The field is now called dest_base. We also need to populate dest_size.

This fixes the build for me although have not tested it. I have a feeling that
loading the kernel from an ELF file on ARM doesn't currently work anyway
(everyone uses the zImage loader as far as I am aware).

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
4.3.0-rc5
2013-06-16 20:22:09 +01:00
Ian Jackson 82cb4113b6 libxc: Better range check in xc_dom_alloc_segment
If seg->pfn is too large, the arithmetic in the range check might
overflow, defeating the range check.

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

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2013-06-14 16:39:38 +01:00
Matthew Daley 966070058d 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>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v8: Add a comment explaining where the number 6 comes from.

v6: This patch is new in v6 of the series.
2013-06-14 16:39:38 +01:00
Ian Jackson de7911eaef 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.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Tim Deegan <tim@xen.org>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>

v6: Check for underflow too (thanks to Andrew Cooper).
2013-06-14 16:39:38 +01:00
Ian Jackson 3d5a1d4733 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.

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

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v8: Move a check in xc_exchange_page to the previous patch
     (ie, remove it from this patch).

v7: Add a missing check for a call to alloc_str.
    Add arithmetic overflow check in xc_dom_malloc.
    Coding style fix.

v6: Fix a missed call `pfn_err = calloc...' in xc_domain_restore.c.
    Fix a missed call `new_pfn = xc_map_foreign_range...' in
     xc_offline_page.c

v5: This patch is new in this version of the series.
2013-06-14 16:39:38 +01:00
Ian Jackson aaebaba5ae 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.

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

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v8: Add a missing check in xc_offline_page.c:xc_exchange_page,
     which was in the next patch in v7 of the series.
     Also improve the message.
     I think in this particular error case it may be that the results
     are a broken guest, but turning this from a possible host tools
     crash into a guest problem seems to solve the potential security
     problem.

v7: Simplify an error DOMPRINTF to not use "load ? : ".
    Make DOMPRINTF allocation error messages consistent.
    Do not set elf->dest_pages in xc_dom_load_elf_kernel
     if xc_dom_seg_to_ptr_pages fails.

v5: This patch is new in this version of the series.
2013-06-14 16:39:38 +01:00
Ian Jackson 2bcee4b3c3 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>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>

v9: Use clearer code for calculating probe_end in find_table.

v6: Add a missing `return -EINVAL' (Matthew Daley).
    Fix an error in the commit message (Matthew Daley).

v5: This patch is new in this version of the series.
2013-06-14 16:39:37 +01:00
Ian Jackson 66fe2726fe 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.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v2: New patch.
2013-06-14 16:39:36 +01:00
Ian Jackson 39bf7b9d0a 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.  Also check that the returned psuedopointer is sane.
 * 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.
 * Some fixed limits to avoid potentially O(image_size^2) loops:
    - maximum length of strings: 4K (longer ones ignored totally)
    - maximum total number of ELF notes: 65536 (any more are ignored)
 * Check that the total program contents (text, data) we copy or
   initialise doesn't exceed twice the output image area size.
 * Remove an entirely useless loop from elf_xen_parse (!)
 * Replace a nested search loop in in xc_dom_load_elf_symtab in
   xc_dom_elfloader.c by a precomputation of a bitmap of referenced
   symtabs.

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.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v8: Fix the two loops in libelf-dominfo.c; the comment about
     PT_NOTE and SHT_NOTE wasn't true because the checks did
     "continue", not "break".
    Add a comment about elf_note_next's expectations of the caller's
     loop conditions (which most plausible callers will follow anyway).

v5: Fix regression due to wrong image size loop limit calculation.
    Check return value from xc_dom_malloc.

v4: Fix regression due to misplacement of test in elf_shdr_by_name
     (uninitialised variable).
    Introduce fixed limits.
    Avoid O(size^2) loops.
    Check returned psuedopointer from elf_note_next is correct.
    A few style fixes.

v3: Fix a whitespace error.

v2: BUGFIX: elf_shdr_by_name, elf_note_next: Reject new <= old, not just <.
    elf_shdr_by_name: Change order of checks to be a bit clearer.
    elf_load_bsdsyms: shdr loop check, improve chance of brokenness detection.
    Style fixes.
2013-06-14 16:39:36 +01:00
Ian Jackson a004800f8f 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.

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>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v8: Use "?!?!" to express consternation instead of a ruder phrase.

v5: Introduce ELF_NOTE_INVALID, instead of using a literal ~0U.

v4: Fix regression in elf_round_up; use uint64_t here.

v3: Changes to booleans split off into separate patch.

v2: BUGFIX: Eliminate conversion to int of return from elf_xen_parse_notes.
    BUGFIX: Fix the one printf format thing which needs changing.
    Remove irrelevant change to constify note_desc.name in libelf-dominfo.c.
    In xc_dom_load_elf_symtab change one sizeof(int) to sizeof(unsigned).
    Do not change type of 2nd argument to memset.
    Provide seddery for easier review.
    Style fix.
2013-06-14 16:39:36 +01:00
Ian Jackson 7a549a6aa0 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>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v3: Use <stdbool.h>'s bool (or _Bool) instead of defining elf_bool.
    Split this into a separate patch.
2013-06-14 16:39:36 +01:00
Ian Jackson c84481fbc7 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.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v5: Fix two whitespace errors.

v3.1:
    Add error check to xc_dom_parse_elf_kernel.
    Move check in xc_hvm_build_x86.c:setup_guest to right place.

v2 was Acked-by: Ian Campbell <ian.campbell@citrix.com>
v2 was Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

v2: Style fixes.
2013-06-14 16:39:36 +01:00
Ian Jackson 943de71cf0 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.

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>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v7: Add a comment about the limited function of elf_is_elfbinary.

v2: Style fix.
    Fix commit message subject.
2013-06-14 16:39:36 +01:00
Ian Jackson 65808a8ed4 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.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v7: Remove a spurious whitespace change.

v5: Use allow_size value from xc_dom_vaddr_to_ptr to set xdest_size
     correctly.
    If ELF_ADVANCE_DEST advances past the end, mark the elf broken.
    Always regard NULL allowable region pointers (e.g. dest_base)
     as invalid (since NULL pointers don't point anywhere).

v4: Fix ELF_UNSAFE_PTR to work on 32-bit even when provided 64-bit
     values.
    Fix xc_dom_load_elf_symtab not to call XC_DOM_PAGE_SIZE
     unnecessarily if load is false.  This was a regression.

v3.1:
    Introduce a change to elf_store_field to undo the effects of
     the v3.1 change to the previous patch (the definition there
     is not compatible with the new types).

v3: Fix a whitespace error.

v2 was Acked-by: Ian Campbell <ian.campbell@citrix.com>

v2: BUGFIX: elf_strval: Fix loop termination condition to actually work.
    BUGFIX: elf_strval: Fix return value to not always be totally wild.
    BUGFIX: xc_dom_load_elf_symtab: do proper check for small header size.
    xc_dom_load_elf_symtab: narrow scope of `hdr_ptr'.
    xc_dom_load_elf_symtab: split out uninit'd symtab.class ref fix.
    More comments on the lifetime/validity of elf-> dest ptrs etc.
    libelf.h: write "obsolete" out in full
    libelf.h: rename "dontuse" to "typeonly" and add doc comment
    elf_ptrval_in_range: Document trustedness of arguments.
    Style and commit message fixes.
2013-06-14 16:39:36 +01:00
Ian Jackson 04877847ad libelf: check nul-terminated strings properly
It is not safe to simply take pointers into the ELF and use them as C
pointers.  They might not be properly nul-terminated (and the pointers
might be wild).

So we are going to introduce a new function elf_strval for safely
getting strings.  This will check that the addresses are in range and
that there is a proper nul-terminated string.  Of course it might
discover that there isn't.  In that case, it will be made to fail.
This means that elf_note_name might fail, too.

For the benefit of call sites which are just going to pass the value
to a printf-like function, we provide elf_strfmt which returns
"(invalid)" on failure rather than NULL.

In this patch we introduce dummy definitions of these functions.  We
introduce calls to elf_strval and elf_strfmt everywhere, and update
all the call sites with appropriate error checking.

There is not yet any semantic change, since before this patch all the
places where we introduce elf_strval dereferenced the value anyway, so
it mustn't have been NULL.

In future patches, when elf_strval is made able return NULL, when it
does so it will mark the elf "broken" so that an appropriate
diagnostic can be printed.

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>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v7: Change readnotes.c check to use two if statements rather than ||.

v2: Fix coding style, in one "if" statement.
2013-06-14 16:39:36 +01:00
Ian Jackson 50421bd56b tools/xcutils/readnotes: adjust print_l1_mfn_valid_note
Use the new PTRVAL macros and elf_access_unsigned in
print_l1_mfn_valid_note.

No functional change unless the input is wrong, or we are reading a
file for a different endianness.

Separated out from the previous patch because this change does produce
a difference in the generated code.

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: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>

v2: Split out into its own patch.
2013-06-14 16:39:36 +01:00
Ian Jackson 8525635999 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.

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.
  * 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>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v7: Add uintptr_t cast to ELF_UNSAFE_PTR.  Still verifies.
    Use git foo not git-foo in commit message verification script.

v4: Fix elf_load_binary's phdr message to be correct on 32-bit.
    Fix ELF_OBSOLETE_VOIDP_CAST to work on 32-bit.
    Indent scripts in commit message.

v3.1:
    Change elf_store_field to verify correctly on 32-bit.
    comparison-generate copes with Xen 4.1's lack of ./configure.

v2: Use Xen style for multi-line comments.
    Postpone changes to readnotes.c:print_l1_mfn_valid_note.
    Much improved verification instructions with new script.
    Fixed commit message subject.

-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__)\.(\d+)\:/) {
         $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 16:39:35 +01:00
Ian Jackson 95dd49bed6 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>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>

v2: Split this change into its own patch for proper review.
2013-06-14 16:39:35 +01:00
Ian Jackson f7aa72ec00 libelf: move include of <asm/guest_access.h> to top of file
libelf-loader.c #includes <asm/guest_access.h>, when being compiled
for Xen.  Currently it does this in the middle of the file.

Move this #include to the top of the file, before libelf-private.h.
This is necessary because in forthcoming patches we will introduce
private #defines of memcpy etc. which would interfere with definitions
in headers #included from guest_access.h.

No semantic or functional change in this patch.

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>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
2013-06-14 16:39:35 +01:00
Ian Jackson 13e2c808f7 libelf: abolish elf_sval and elf_access_signed
These are not used anywhere.

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: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
2013-06-14 16:39:34 +01:00
Ian Jackson 009ddca515 libelf: add `struct elf_binary*' parameter to elf_load_image
The meat of this function is going to need a copy of the elf pointer,
in forthcoming patches.

No functional change in this patch.

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>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
2013-06-14 16:39:34 +01:00
Ian Jackson b5a8692099 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>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

v5: This patch is new in v5 of the series.
2013-06-14 16:39:34 +01:00
Ian Jackson 53bfcf585b 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>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>

v7: xc_dom_seg_to_ptr_pages now always expects pages_out!=NULL.
   (It seems silly to have it tolerate NULL when all the real callers
    pass non-NULL and there's a version which doesn't need pages_out
    anyway.  Fix the call in xc_dom_seg_to_ptr to have a dummy pages
    for pages_out.)

v5: xc_dom_seg_to_ptr_pages sets *pages_out=0 if it returns NULL.

v4 was:

Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2013-06-14 16:39:34 +01:00
Ian Jackson 14573b9748 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>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
2013-06-14 16:39:34 +01:00
Ian Jackson 1fee00908a Update QEMU_UPSTREAM_REVISION
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
2013-06-14 12:34:52 +01:00
Julien Grall 2caac1caa1 xen/arm: Use the right GICD register to initialize IRQs routing
Currently IRQs routing is initialized to the wrong register and overwrites
interrupt configuration register (ICFGRn).

Reported-by: Sander Bogaert <sander.bogaert@elis.ugent.be>
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2013-06-13 17:48:17 +01:00
Stefano Stabellini c4cf4c30a8 xen/arm: define PAGE_HYPERVISOR as WRITEALLOC
Use stage 1 attribute indexes for PAGE_HYPERVISOR, the appriopriate one
for normal memory hypervisor mappings in Xen is WRITEALLOC.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2013-06-13 17:45:33 +01:00
Ian Campbell 97e3e84c6d xen/arm64: fix stack dump in show_trace
On aarch64 the frame pointer points to the next frame pointer and the return
address is the previous stack slot (so below on the downward growing stack,
therefore above in memory):

       |<RETURN ADDR>      ^addresses grow up
 FP -> |<NEXT FP>          |
       |                   |
       v                   |
       stack grows down.

This is contrary to aarch32 where the frame pointer points to the return
address and the next frame pointer is the next stack slot (so above on the
downward growing stack, below in memory):

 FP -> |<RETURN ADDR>       ^addresses grow up
       |<NEXT FP>           |
       |                    |
       v                    |
       stack grows down.

In addition print out LR as part of the trace, since it may contain the
penultimate return address e.g. if the ultimate function is a leaf function.

Lastly nuke some unnecessary braces.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-06-13 17:42:13 +01:00
Konrad Rzeszutek Wilk 0c6781ee6a tmem: Don't use map_domain_page for long-life-time pages
When using tmem with Xen 4.3 (and debug build) we end up with:

(XEN) Xen BUG at domain_page.c:143
(XEN) ----[ Xen-4.3-unstable  x86_64  debug=y  Not tainted ]----
(XEN) CPU:    3
(XEN) RIP:    e008:[<ffff82c4c01606a7>] map_domain_page+0x61d/0x6e1
..
(XEN) Xen call trace:
(XEN)    [<ffff82c4c01606a7>] map_domain_page+0x61d/0x6e1
(XEN)    [<ffff82c4c01373de>] cli_get_page+0x15e/0x17b
(XEN)    [<ffff82c4c01377c4>] tmh_copy_from_client+0x150/0x284
(XEN)    [<ffff82c4c0135929>] do_tmem_put+0x323/0x5c4
(XEN)    [<ffff82c4c0136510>] do_tmem_op+0x5a0/0xbd0
(XEN)    [<ffff82c4c022391b>] syscall_enter+0xeb/0x145
(XEN)

A bit of debugging revealed that the map_domain_page and unmap_domain_page
are meant for short life-time mappings. And that those mappings are finite.
In the 2 VCPU guest we only have 32 entries and once we have exhausted those
we trigger the BUG_ON condition.

The two functions - tmh_persistent_pool_page_[get,put] are used by the xmem_pool
when xmem_pool_[alloc,free] are called. These xmem_pool_* function are wrapped
in macro and functions - the entry points are via: tmem_malloc
and tmem_page_alloc. In both cases the users are in the hypervisor and they
do not seem to suffer from using the hypervisor virtual addresses.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-13 16:09:03 +02:00
Jan Beulich 61c6dfce32 x86: fix map_domain_page() last resort fallback
Guests with vCPU count not divisible by 4 have unused bits in the last
word of their inuse bitmap, and the garbage collection code therefore
would get mislead believing that some entries were actually recoverable
for use.

Also use an earlier established local variable in mapcache_vcpu_init()
instead of re-calculating the value (noticed while investigating the
generally better option of setting those overhanging bits once during
setup - this didn't work out in a simple enough fashion because the
mapping getting established there isn't in the current address space,
and hence the bitmap isn't directly accessible there).

Reported-by: Konrad Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
2013-06-13 10:49:01 +02:00
Jan Beulich fd0b066895 x86: drop setup_idle_pagetable()
With vcpu->domain->arch.perdomain_l3_pg no longer getting set up for
the idle domain, this creates an invalid L4 entry (due to translating
a NULL struct page_info pointer to a physical address).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
2013-06-12 17:27:08 +02:00
George Dunlap 4015145b14 docs: Make note for the scheduler "cap" option warning about power management effects
Suggested-by: Massimo Canonico <mex@di.unipmn.it>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2013-06-12 10:42:37 +01:00
Dario Faggioli 16f3499417 libxl: add LIBXL_HAVE_<foo> for outstanding_pages and outstanding_memkb
Commits d0782481  ("xl: export 'outstanding_pages' value from xcinfo")
and bec8f17e ("xen: Remove the XENMEM_get_oustanding_pages and provide
the data via xc_phys_info") added these two fields in libxl_physinfo
and in libxl_dominfo, respectively, but did not include the needed
LIBXL_HAVE_<foo> runes. Adding them.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
2013-06-12 10:11:27 +01:00
Daniel De Graaf b61b893d20 flask/policy: device model stubdom fixes
This fixes framebuffer support for device model stubdoms after 3f28d007
which added the target_hack permission but did not allow the permission
to the stubdom it was created for.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2013-06-12 10:09:15 +01:00
Jan Beulich 613659da9b io/ring.h: drop unused and broken *_RING_ATTACH() macros
Initializing r*_prod_pvt and r*_cons from independent shared ring
fields is broken, as other macros in this header rely on them being
coupled. Furthermore using the backend variant would also imply a
security vulnerability.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
2013-06-12 10:07:48 +02:00
Jan Beulich a63c57093b io/ring.h: new macro to detect whether there are too many requests on the ring
Backends may need to protect themselves against an insane number of
produced requests stored by a frontend, in case they iterate over
requests until reaching the req_prod value. There can't be more
requests on the ring than the difference between produced requests
and produced (but possibly not yet published) responses.

This is a more strict alternative to a patch previously posted by
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
2013-06-12 10:07:20 +02:00
Roger Pau Monné f8e8fd56bd x86/HVM: fix initialization of wallclock time for PVHVM on migration
Call update_domain_wallclock_time on hvm_latch_shinfo_size even if
the bitness of the guest has already been set, this fixes the problem
with the wallclock not being set for PVHVM guests on resume from
migration.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>

Clean up the resulting code and retain the (slightly adjusted) original
comment.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
2013-06-12 10:05:39 +02:00
Zhenguo Wang 6859874b61 x86/HVM: fix x2APIC APIC_ID read emulation
APIC and x2APIC have different format for APIC_ID register. Need
translation.

Signed-off-by: Zhenguo Wang <wangzhenguo@huawei.com>
Signed-off-by: Xiaowei Yang <xiaowei.yang@huawei.com>

Convert code to use switch(), fixing coding style issue at once, and
use GET_xAPIC_ID() on the value read instead of VLAPIC_ID() (reading
the field again).

In the course of this also properly reject both read and writes on the
non-existing MSR corresponding to APIC_ICR2.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
2013-06-11 09:45:55 +02:00
Jan Beulich 44434f3c5e gnttab: drop unused GNTCOPY_can_fail
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
4.3.0-rc4
2013-06-10 14:42:51 +02:00
Jan Beulich ac9e298cb4 Revert "irq: Add extra debugging to help track down why an assertion is failing"
This reverts commits 2ae8b9173f and
98e10364bd.

This was never reported to be hit, and we assume to have taken care of
the problem by excluding legacy IRQs from the IRQ move cleanup logic.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
2013-06-10 13:43:03 +02:00
Jan Beulich e430510e5c AMD/IOMMU: revert "SR56x0 Erratum 64 - Reset all head & tail pointers"
The code this patch added is redundant with already present code in
set_iommu_{command_buffer,{event,ppr}_log}_control(). Just switch those
ones from using writel() to writeq() for consistency.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
2013-06-05 10:05:49 +02:00
Roger Pau Monné 32c864a35e x86/vtsc: update vcpu_time in hvm_set_guest_time
When using a vtsc, hvm_set_guest_time changes hvm_vcpu.stime_offset,
which is used in the vcpu time structure to calculate the
tsc_timestamp, so after updating stime_offset we need to propagate the
change to vcpu_time in order for the guest to get the right time if
using the PV clock.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
2013-06-05 10:03:08 +02:00
Jan Beulich 10b2b21a24 x86: fix XCR0 handling
- both VMX and SVM ignored the ECX input to XSETBV
- both SVM and VMX used the full 64-bit RAX when calculating the input
  mask to XSETBV
- faults on XSETBV did not get recovered from

Also consolidate the handling for PV and HVM into a single function,
and make the per-CPU variable "xcr0" static to xstate.c.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
2013-06-04 17:25:41 +02:00
Jan Beulich 10f9691500 x86: preserve FPU selectors for 32-bit guest code
Doing {,F}X{SAVE,RSTOR} unconditionally with 64-bit operand size leads
to the selector values associated with the last instruction/data
pointers getting lost. This, besides being inconsistent and not
compatible with native hardware behavior especially for 32-bit guests,
leads to bug checks in 32-bit Windows when running with "Driver
verifier" (see e.g. http://support.microsoft.com/kb/244617).

In a first try I made the code figure out the current guest mode, but
that has the disadvantage of only taking care of the issue when the
guest executes in the mode for which the state currently is (i.e.
namely not in the case of a 64-bit guest running a 32-bit application,
but being in kernle [64-bit] mode).

The solution presented here is to conditionally execute an auxiliary
FNSTENV and use the selectors from there.

In either case the determined word size gets stored in the last byte
of the FPU/SSE save area, which is available for software use (and I
verified is being cleared to zero by all versions of Xen, i.e. will not
present a problem when migrating guests from older to newer hosts), and
evaluated for determining the operand size {,F}XRSTOR is to be issued
with.

Note that I did check whether using a second FXSAVE or a partial second
XSAVE would be faster than FNSTENV - neither on my Westmere (FXSAVE)
nor on my Romley (XSAVE) they are.

I was really tempted to use branches into the middle of instructions
(i.e. past the REX64 prefixes) here, as that would have allowed to
collapse the otherwise identical fault recovery blocks. I stayed away
from doing so just because I expect others to dislike such slightly
subtle/tricky code.

Reported-by: Ben Guthro <Benjamin.Guthro@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
2013-06-04 17:23:11 +02:00
Jan Beulich 365c95f7de x86/xsave: properly check guest input to XSETBV
Other than the HVM emulation path, the PV case so far failed to check
that YMM state requires SSE state to be enabled, allowing for a #GP to
occur upon passing the inputs to XSETBV inside the hypervisor.

This is CVE-2013-2078 / XSA-54.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
2013-06-04 09:29:07 +02:00
Jan Beulich c6ae65db36 x86/xsave: recover from faults on XRSTOR
Just like FXRSTOR, XRSTOR can raise #GP if bad content is being passed
to it in the memory block (i.e. aspects not under the control of the
hypervisor, other than e.g. proper alignment of the block).

Also correct the comment explaining why FXRSTOR needs exception
recovery code to not wrongly state that this can only be a result of
the control tools passing a bad image.

This is CVE-2013-2077 / XSA-53.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
2013-06-04 09:27:58 +02:00
Jan Beulich 8dcf9f0113 x86/xsave: fix information leak on AMD CPUs
Just like for FXSAVE/FXRSTOR, XSAVE/XRSTOR also don't save/restore the
last instruction and operand pointers as well as the last opcode if
there's no pending unmasked exception (see CVE-2006-1056 and commit
9747:4d667a139318).

While the FXSR solution sits in the save path, I prefer to have this in
the restore path because there the handling is simpler (namely in the
context of the pending changes to properly save the selector values for
32-bit guest code).

Also this is using FFREE instead of EMMS, as it doesn't seem unlikely
that in the future we may see CPUs with x87 and SSE/AVX but no MMX
support. The goal here anyway is just to avoid an FPU stack overflow.
I would have preferred to use FFREEP instead of FFREE (freeing two
stack slots at once), but AMD doesn't document that instruction.

This is CVE-2013-2076 / XSA-52.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
2013-06-04 09:26:54 +02:00
Aravindh Puthiyaparambil 5cffb77c40 x86/MCE: disable if MCE banks are not present
When booting Xen on VMware ESX 5.1 and Workstation 9, you hit a GPF
during MCE initialization. The culprit is line 631 in
set_poll_bankmask():
                bitmap_copy(mb->bank_map, mca_allbanks->bank_map, nr_mce_banks);

What is happening is that in mca_cap_init(), nr_mce_banks is being set
to 0. This causes the allocation of bank_map to be set to
ZERO_BLOCK_PTR which is the return value for zero-size allocation by
xzalloc_array()/_xmalloc(). This results in the bitmap_copy() to fail
disastrously. The following patch fixes this issue.

Signed-off-by: Aravindh Puthiyaparambil <aravindp@cisco.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christoph Egger <chegger@amazon.de>
2013-06-03 15:42:46 +02:00