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* QEMU_UPSTREAM_REVISION update4.3.0-rc6Ian Jackson2013-06-271-1/+1
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* libxl: Use QMP cpu-add to hotplug CPU with qemu-xen.Anthony PERARD2013-06-261-6/+46
| | | | | | Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxl: Add "cpu-add" QMP command.Anthony PERARD2013-06-262-0/+23
| | | | | | | Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> [ ijc -- rename index parameter to avoid Wshadow due to index(3) in strings.h ]
* Update SEABIOS_UPSTREAM_TAGIan Campbell2013-06-261-3/+3
| | | | Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
* Merge branch 'staging' of ssh://xenbits.xen.org/home/xen/git/xen into stagingIan Campbell2013-06-264-9/+29
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| * also override library path for hotplug scriptsJan Beulich2013-06-261-0/+1
| | | | | | | | | | | | | | | | | | Overriding PATH but not LD_LIBRARY_PATH is bogus, as it may result in the use of mismatched binaries and libraries. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
| * x86: fix page refcount handling in page table pin error pathJan Beulich2013-06-263-9/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the original patch 7 of the series addressing XSA-45 I mistakenly took the addition of the call to get_page_light() in alloc_page_type() to cover two decrements that would happen: One for the PGT_partial bit that is getting set along with the call, and the other for the page reference the caller hold (and would be dropping on its error path). But of course the additional page reference is tied to the PGT_partial bit, and hence any caller of a function that may leave ->arch.old_guest_table non-NULL for error cleanup purposes has to make sure a respective page reference gets retained. Similar issues were then also spotted elsewhere: In effect all callers of get_page_type_preemptible() need to deal with errors in similar ways. To make sure error handling can work this way without leaking page references, a respective assertion gets added to that function. This is CVE-2013-1432 / XSA-58. Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Tested-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Tim Deegan <tim@xen.org>
* | tools/libxc: Fix memory leaks in xc_domain_save()Andrew Cooper2013-06-261-0/+9
| | | | | | | | | | | | | | | | Introduces outbuf_free() to mirror the currently existing outbuf_init(). Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* | libxc: Fix guest boot on ARM after XSA-55Julien Grall2013-06-262-4/+7
| | | | | | | | | | | | | | | | 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>
* | libxl: Fix assignment of devid value returned from libxl__device_nextidJim Fehlig2013-06-261-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5420f265 has some misplaced parenthesis that caused devid to be assigned 1 or 0 based on checking return value of libxl__device_nextid < 0, e.g. devid = libxl__device_nextid(...) < 0 This works when only one instance of a given device type exists, but subsequent devices of the same type will also have a devid = 1 if libxl__device_nextid succeeds. Fix by checking the value assigned to devid, e.g. (devid = libxl__device_nextid(...)) < 0 Signed-off-by: Jim Fehlig <jfehlig@suse.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* | libelf: fix printing of pointersJan Beulich2013-06-261-4/+4
|/ | | | | | | Printing them as decimal number, the more with 0x prefix, is confusing and presumably relatively useless to most of us. Signed-off-by: Jan Beulich <jbeulich@suse.com>
* docs: Update xenstore-paths.markdown with new hvmloader keyGeorge Dunlap2013-06-261-0/+8
| | | | | | Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> Acked-by: Ian Jackson <ian.jackson@citrix.com>
* VMX/Viridian: suppress MSR-based APIC suggestion when having APIC-VJan Beulich2013-06-251-2/+3
| | | | | | | | | | | When the CPU has the necessary capabilities, having Windows use synthetic MSR reads/writes is bogus, as this still requires emulation (which is pretty much guaranteed to be slower than having the hardware carry out the operation). Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
* libxl: Restrict permissions on PV console device xenstore nodesIan Jackson2013-06-256-42/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Matthew Daley has observed that the PV console protocol places sensitive host state into a guest writeable xenstore locations, this includes: - The pty used to communicate between the console backend daemon and its client, allowing the guest administrator to read and write arbitrary host files. - The output file, allowing the guest administrator to write arbitrary host files or to target arbitrary qemu chardevs which include sockets, udp, ptr, pipes etc (see -chardev in qemu(1) for a more complete list). - The maximum buffer size, allowing the guest administrator to consume more resources than the host administrator has configured. - The backend to use (qemu vs xenconsoled), potentially allowing the guest administrator to confuse host software. So we arrange to make the sensitive keys in the xenstore frontend directory read only for the guest. This is safe since the xenstore permissions model, unlike POSIX directory permissions, does not allow the guest to remove and recreate a node if it has write access to the containing directory. There are a few associated wrinkles: - The primary PV console is "special". It's xenstore node is not under the usual /devices/ subtree and it does not use the customary xenstore state machine protocol. Unfortunately its directory is used for other things, including the vnc-port node, which we do not want the guest to be able to write to. Rather than trying to track down all the possible secondary uses of this directory just make it r/o to the guest. All newly created subdirectories inherit these permissions and so are now safe by default. - The other serial consoles do use the customary xenstore state machine and therefore need write access to at least the "protocol" and "state" nodes, however they may also want to use arbitrary "feature-foo" nodes (although I'm not aware of any) and therefore we cannot simply lock down the entire frontend directory. Instead we add support to libxl__device_generic_add for frontend keys which are explicitly read only and use that to lock down the sensitive keys. - Minios' console frontend wants to write the "type" node, which it has no business doing since this is a host/toolstack level decision. This fails now that the node has become read only to the PV guest. Since the toolstack already writes this node just remove the attempt to set it. This is a security issue, XSA-57. Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
* tools/libxc: Fix memory leaks in xc_domain_restore()Andrew Cooper2013-06-241-0/+3
| | | | | | Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> (re 4.3 release) Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
* libxl,hvmloader: Don't relocate memory for MMIO holeGeorge Dunlap2013-06-243-2/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the moment, qemu-xen can't handle memory being relocated by hvmloader. This may happen if a device with a large enough memory region is passed through to the guest. At the moment, if this happens, then at some point in the future qemu will crash and the domain will hang. (qemu-traditional is fine.) It's too late in the release to do a proper fix, so we try to do damage control. hvmloader already has mechanisms to relocate memory to 64-bit space if it can't make a big enough MMIO hole. By default this is 2GiB; if we just refuse to make the hole bigger if it will overlap with guest memory, then the relocation will happen by default. v5: - Update comment to not refer to "this series". v4: - Wrap long line in libxl_dm.c - Fix comment v3: - Fix polarity of comparison - Move diagnostic messages to another patch - Tested with xen platform pci device hacked to have different BAR sizes {256MiB, 1GiB} x {qemu-xen, qemu-traditional} x various memory configurations - Add comment explaining why we default to "allow" - Remove cast to bool v2: - style fixes - fix and expand comment on the MMIO hole loop - use "%d" rather than "%s" -> (...)?"1":"0" - use bool instead of uint8_t - Move 64-bit bar relocate detection to another patch - Add more diagnostic messages Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Stefano Stabellini <stefano.stabellini@citrix.com> CC: Hanweidong <hanweidong@huawei.com> CC: Keir Fraser <keir@xen.org> CC: Keir Fraser <keir@xen.org>
* hvmloader: Remove minimum size for BARs to relocate to 64-bit spaceGeorge Dunlap2013-06-242-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | Allow devices with BARs less than 512MiB to be relocated to high memory. This will only be invoked if there is not enough low MMIO space to map the device, and will be done preferentially to large devices first; so in all likelihood only large devices will be remapped anyway. This is needed to work-around the issue of qemu-xen not being able to handle moving guest memory around to resize the MMIO hole. The default MMIO hole size is less than 256MiB. v3: - Fixed minor style issue Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Hanweidong <hanweidong@huawei.com> CC: Keir Fraser <keir@xen.org>
* hvmloader: Load large devices into high MMIO space as neededGeorge Dunlap2013-06-241-1/+7
| | | | | | | | | | | | | | | | | | | | | | | Keep track of how much mmio space is left total, as well as the amount of "low" MMIO space (<4GiB), and only load devices into high memory if there is not enough low memory for the rest of the devices to fit. Because devices are processed by size in order from large to small, this should preferentially relocate devices with large BARs to 64-bit space. v3: - Just use mmio_total rather than introducing a new variable. - Port to using mem_resource directly rather than low_mmio_left Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Stefano Stabellini <stefano.stabellini@citrix.com> CC: Hanweidong <hanweidong@huawei.com> CC: Keir Fraser <keir@xen.org>
* hvmloader: Correct bug in low mmio region accountingGeorge Dunlap2013-06-241-5/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When deciding whether to map a device in low MMIO space (<4GiB), hvmloader compares it with "mmio_left", which is set to the size of the low MMIO range (pci_mem_end - pci_mem_start). However, even if it does map a device in high MMIO space, it still removes the size of its BAR from mmio_left. In reality we don't need to do a separate accounting of the low memory available -- this can be calculated from mem_resource. Just get rid of the variable and the duplicate accounting entirely. This will make the code more robust. Note also that the calculation of whether to move a device to 64-bit is fragile at the moment, depending on some unstated assumptions. State those assumptions in a comment for future reference. v5: - Add comment documenting fragility of the move-to-highmem check v3: - Use mem_resource values directly instead of doing duplicate accounting Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Stefano Stabellini <stefano.stabellini@citrix.com> CC: Hanweidong <hanweidong@huawei.com> CC: Keir Fraser <keir@xen.org>
* hvmloader: Fix check for needing a 64-bit barGeorge Dunlap2013-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | After attempting to resize the MMIO hole, the check to determine whether there is a need to relocate BARs into 64-bit space checks the specific thing that caused the loop to exit (MMIO hole == 2GiB) rather than checking whether the required MMIO will fit in the hole. But even then it does it wrong: the polarity of the check is backwards. Check for the actual condition we care about (the sizeof the MMIO hole) rather than checking for the loop exit condition. v3: - Move earlier in the series, before other functional changes Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> CC: Ian Jackson <ian.jackson@citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Stefano Stabellini <stefano.stabellini@citrix.com> CC: Hanweidong <hanweidong@huawei.com> CC: Keir Fraser <keir@xen.org>
* hvmloader: Set up highmem resouce appropriately if there is no RAM above 4GGeorge Dunlap2013-06-241-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | hvmloader will read hvm_info->high_mem_pgend to calculate where to start the highmem PCI region. However, if the guest does not have any memory in the high region, this is set to zero, which will cause hvmloader to use the "0" for the base of the highmem region, rather than 1 << 32. Check to see whether hvm_info->high_mem_pgend is set; if so, do the normal calculation; otherwise, use 1<<32. v4: - Handle case where hfm_info->high_mem_pgend is non-zero but doesn't point into high memory, throwing a warning. Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Ian Jackson <ian.jackson@citrix.com> CC: Stefano Stabellini <stefano.stabellini@citrix.com> CC: Hanweidong <hanweidong@huawei.com> CC: Keir Fraser <keir@xen.org>
* hvmloader: Make the printfs more informativeGeorge Dunlap2013-06-241-2/+11
| | | | | | | | | | | | | | | | | | | | | | | * Warn that you're relocating some BARs to 64-bit * Warn that you're relocating guest pages, and how many * Include upper 32-bits of the base register when printing the bar placement info v4: - Move message about relocating guest pages into loop, include number of pages and guest paddr - Fixed minor brace style issue Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Ian Jackson <ian.jackson@citrix.com> CC: Stefano Stabellini <stefano.stabellini@citrix.com> CC: Hanweidong <hanweidong@huawei.com> CC: Keir Fraser <keir@xen.org>
* hvmloader: Remove all 64-bit print argumentsGeorge Dunlap2013-06-242-4/+9
| | | | | | | | | | | | | | | | | | The printf() available to hvmloader does not handle 64-bit data types; manually break them down as two 32-bit strings. v4: - Make macros for the requisite format and bit shifting Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Keir Fraser <keir@xen.org> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Ian Jackson <ian.jackson@citrix.com> CC: Stefano Stabellini <stefano.stabellini@citrix.com> CC: Hanweidong <hanweidong@huawei.com> CC: Keir Fraser <keir@xen.org>
* x86/hvm: fix HVMOP_inject_trap return value on successTim Deegan2013-06-211-0/+1
| | | | | | | Reported-by: Antony Saba <Antony.Saba@mandiant.com> Signed-off-by: Tim Deegan <tim@xen.org> Acked-by: Keir Fraser <keir@xen.org> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
* tpmif: fix identifier prefixesJan Beulich2013-06-214-32/+32
| | | | | | | | | | The definitions here shouldn't use vtpm_ or VPTM_ as their prefixes, the interface should instead make use of tpmif_ and TPMIF_. This fixes a build failure after syncing the public headers to linux-2.6.18-xen.hg (where a struct vtpm_state already exists). Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
* QEMU_TAG updateIan Jackson2013-06-171-3/+3
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* AMD IOMMU: make interrupt work againJan Beulich2013-06-173-9/+18
| | | | | | | | | | | | | | | | | | | | 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>
* xen: arm: fix build after libelf changes.4.3.0-rc5Ian Campbell2013-06-161-1/+3
| | | | | | | | | | | | | | | | 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>
* libxc: Better range check in xc_dom_alloc_segmentIan Jackson2013-06-141-1/+2
| | | | | | | | | | 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>
* libxc: check blob size before proceeding in xc_dom_check_gzipMatthew Daley2013-06-141-0/+5
| | | | | | | | | | | | | 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.
* libxc: range checks in xc_dom_p2m_host and _guestIan Jackson2013-06-141-0/+4
| | | | | | | | | | | | | | | | | | | 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).
* libxc: check return values from mallocIan Jackson2013-06-149-3/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* libxc: check failure of xc_dom_*_to_ptr, xc_map_foreign_rangeIan Jackson2013-06-147-0/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* libxc: Add range checking to xc_dom_binloaderIan Jackson2013-06-141-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* libelf: abolish obsolete macrosIan Jackson2013-06-146-68/+44
| | | | | | | | | | | | | | | | 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.
* libelf: check loops for running awayIan Jackson2013-06-145-29/+135
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* libelf: use only unsigned integersIan Jackson2013-06-149-87/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* libelf: use C99 bool for booleansIan Jackson2013-06-146-21/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* libelf: Make all callers call elf_check_brokenIan Jackson2013-06-145-11/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* libelf: Check pointer references in elf_is_elfbinaryIan Jackson2013-06-145-8/+13
| | | | | | | | | | | | | | | | | | | | | | 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.
* libelf: check all pointer accessesIan Jackson2013-06-148-85/+312
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* libelf: check nul-terminated strings properlyIan Jackson2013-06-144-11/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* tools/xcutils/readnotes: adjust print_l1_mfn_valid_noteIan Jackson2013-06-141-5/+6
| | | | | | | | | | | | | | | | | | | | 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.
* libelf: introduce macros for memory access and pointer handlingIan Jackson2013-06-147-163/+312
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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<-
* libelf/xc_dom_load_elf_symtab: Do not use "syms" uninitialisedIan Jackson2013-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | 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.
* libelf: move include of <asm/guest_access.h> to top of fileIan Jackson2013-06-141-1/+4
| | | | | | | | | | | | | | | | | | | | 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>
* libelf: abolish elf_sval and elf_access_signedIan Jackson2013-06-142-39/+0
| | | | | | | | | | | 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>
* libelf: add `struct elf_binary*' parameter to elf_load_imageIan Jackson2013-06-141-3/+5
| | | | | | | | | | | | | | | 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>
* libxc: Fix range checking in xc_dom_pfn_to_ptr etc.Ian Jackson2013-06-144-5/+38
| | | | | | | | | | | | | | | | | | | | | * 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.
* libxc: introduce xc_dom_seg_to_ptr_pagesIan Jackson2013-06-141-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | 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>