Coverity ID 1055563
In the original function, mmap() could be called with a length of -1 if the
second lseek failed and the caller had not provided max_size.
While fixing up this error, improve the logging of other error paths. I know
from personal experience that debugging failures function is rather difficult
given only "xc_dom_malloc_filemap: failed (on file <somefile>)" in the logs.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
Acked-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
(cherry picked from commit c635c1ef78)
XSA-55 has exposed errors for guest creation on ARM:
- domain virt_base was not defined;
- xc_dom_alloc_segment allocates pfn from 0 instead of the RAM base address.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
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>
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.
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.
* 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.
The emacs variable to set the C style from a local variable block is
c-file-style, not c-set-style.
Signed-off-by: David Vrabel <david.vrabel@citrix.com
In particular we need to check that adding 512KB of slack and
rounding up to a 4MB boundary do not overflow the guest's memory
allocation. Otherwise we run off the end of the p2m when building the
guest's initial page tables and populate them with garbage.
Wei noticed this when build tiny (2MB) mini-os domains.
Reported-by: Wei Liu <Wei.Liu2@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
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>
The goto in both of these places misses the event free which would
normally clean up.
==8655== 80 bytes in 1 blocks are definitely lost in loss record 1 of 1
==8655== at 0x4024370: calloc (vg_replace_malloc.c:593)
==8655== by 0x406EAAE: libxl__zalloc (libxl_internal.c:83)
==8655== by 0x4078173: libxl__event_new (libxl_event.c:1167)
==8655== by 0x4056373: domain_death_occurred (libxl.c:958)
==8655== by 0x4058D06: domain_death_xswatch_callback (libxl.c:1038)
==8655== by 0x4078EB5: watchfd_callback (libxl_event.c:458)
==8655== by 0x407839E: afterpoll_internal (libxl_event.c:949)
==8655== by 0x4079142: eventloop_iteration (libxl_event.c:1371)
==8655== by 0x40799BB: libxl_event_wait (libxl_event.c:1396)
==8655== by 0x805CC67: create_domain (xl_cmdimpl.c:1698)
==8655== by 0x805E001: main_create (xl_cmdimpl.c:3986)
==8655== by 0x804D43D: main (xl.c:285)
Signed-off-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>
# User Ian Campbell <ian.campbell@citrix.com>
# Date 1282671421 -3600
# Node ID d1dd29a470ef1b9d2c77478a123326036dfe90bb
# Parent d7a4adad9c328decbd384d87b23001aea8951b86
tools/libxc, tools/libelf: Relicense under LGPL v2.1
Relicense these two libraries under LGPL v2.1 only except where
individual files already included the "or later" provision.
Copyright holders have been contacted by Stephen Spector and have all
agreed this change.
Removed tools/libxc/ia64/aclinux.h since it appeared to be
unused. There is a separate, more up to date, copy in
xen/include/acpi/platform/aclinux.h which does appear to be used.
Clarify the license of MiniOS privcmd.h under the same terms as other
tools/include/xen-sys headers.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stephen Spector <stephen.spector@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
This patch eliminate the global variables in libxenctrl (used for
logging and error reporting).
Instead the information which was in the global variables is now in a
new xc_interface* opaque structure, which xc_interface open returns
instead of the raw file descriptor; furthermore, logging is done via
xentoollog.
There are three new parameters to xc_interface_open to control the
logging, but existing callers can just pass "0" for all three to get
the old behaviour.
All libxc callers have been adjusted accordingly.
Also update QEMU_TAG for corresponding qemu change.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Previously, xc_dom_alloc_segment would go ahead even if the segment
we're trying to create is too big for the domain's RAM (or the
requested addr is out of range). It would pass invalid parameters to
xc_dom_seg_to_ptr giving undefined behaviour.
Fixing xc_dom_seg_to_ptr to fail is not sufficient because we want to
provide a comprehensible explanation to the caller - which may
ultimately be the user.
In particular, with this change attempting "xl create" with a ramdisk
image bigger than the guest's specified RAM will provide a useful
error message mentioning the ramdisk.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Previously, passing a valid pfn but an overly large count to
xc_dom_pfn_to_ptr, and functions which call it, would run off the end
of the pfn array giving undefined behaviour.
It is tempting to change this check to an assert, as no callers should
be providing invalid parameters here. But this is probably best not
done while frozen for 4.0.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
This fetches GRUB1 sources, applies the {graphical, print function,
save default, and ext3_256byte} patches from debian, and applies a
patch to make it work on x86_64 and port it to Mini-OS. By using
libxc, PV-GRUB can then "kexec" the loaded kernel from inside the
domain itself, hence permitting to avoid the security-concerned
pygrub.
Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>
- use MAP_ANON, that is what both (BSD-)Unix and Linux have
- change last_error handling to use pthreads
- round mlock() parameters to page alignment
- cleanup: No need to include <xen/sys/privcmd.h>
a second time in xg_private.h
Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
Signed-off-by: Keir Fraser <keir@xensource.com>
Andrew Cooper
Julien Grall
Ian Jackson
Matthew Daley
David Vrabel
Ian Campbell
Keir Fraser
kfraser@localhost.localdomain
Hollis Blanchard
Christian Limpach
Keir Fraser
Emmanuel Ackaouy