linux/mm
Andi Kleen 42e4089c78 x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings
For L1TF PROT_NONE mappings are protected by inverting the PFN in the page
table entry. This sets the high bits in the CPU's address space, thus
making sure to point to not point an unmapped entry to valid cached memory.

Some server system BIOSes put the MMIO mappings high up in the physical
address space. If such an high mapping was mapped to unprivileged users
they could attack low memory by setting such a mapping to PROT_NONE. This
could happen through a special device driver which is not access
protected. Normal /dev/mem is of course access protected.

To avoid this forbid PROT_NONE mappings or mprotect for high MMIO mappings.

Valid page mappings are allowed because the system is then unsafe anyways.

It's not expected that users commonly use PROT_NONE on MMIO. But to
minimize any impact this is only enforced if the mapping actually refers to
a high MMIO address (defined as the MAX_PA-1 bit being set), and also skip
the check for root.

For mmaps this is straight forward and can be handled in vm_insert_pfn and
in remap_pfn_range().

For mprotect it's a bit trickier. At the point where the actual PTEs are
accessed a lot of state has been changed and it would be difficult to undo
on an error. Since this is a uncommon case use a separate early page talk
walk pass for MMIO PROT_NONE mappings that checks for this condition
early. For non MMIO and non PROT_NONE there are no changes.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
2018-06-20 19:10:01 +02:00
..
kasan kasan: fix memory hotplug during boot 2018-05-25 18:12:11 -07:00
backing-dev.c memcg: writeback: use memcg->cgwb_list directly 2018-06-07 17:34:36 -07:00
balloon_compaction.c virtio_balloon: fix deadlock on OOM 2017-11-14 23:57:38 +02:00
bootmem.c mm: docs: fix parameter names mismatch 2018-02-06 18:32:48 -08:00
cleancache.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
cma_debug.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
cma.c Revert "mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE" 2018-05-24 10:07:50 -07:00
cma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compaction.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
debug_page_ref.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug.c mm/debug.c: provide useful debugging information for VM_BUG 2018-01-04 16:45:09 -08:00
dmapool.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
early_ioremap.c mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep 2017-12-11 14:54:44 +01:00
fadvise.c mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64() 2018-04-02 20:16:10 +02:00
failslab.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
filemap.c mm: use new return type vm_fault_t 2018-06-07 17:34:36 -07:00
frame_vector.c mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()' 2017-12-14 16:00:48 -08:00
frontswap.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
gup_benchmark.c treewide: kvzalloc() -> kvcalloc() 2018-06-12 16:19:22 -07:00
gup.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
highmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hmm.c mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS 2018-05-22 06:59:39 -07:00
huge_memory.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
hugetlb_cgroup.c mm: rename page_counter's count/limit into usage/max 2018-06-07 17:34:35 -07:00
hugetlb.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
hwpoison-inject.c mm/memory_failure: Remove unused trapno from memory_failure 2018-01-23 12:17:42 -06:00
init-mm.c mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct 2018-06-07 17:34:34 -07:00
internal.h Changes for 4.18: 2018-06-05 13:24:20 -07:00
interval_tree.c mm/interval_tree.c: use vma_pages() helper 2018-01-31 17:18:37 -08:00
Kconfig libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
Kconfig.debug kmemcheck: rip it out 2017-11-15 18:21:05 -08:00
khugepaged.c page cache: use xa_lock 2018-04-11 10:28:39 -07:00
kmemleak-test.c
kmemleak.c mm: kernel-doc: add missing parameter descriptions 2018-04-05 21:36:27 -07:00
ksm.c mm/ksm.c: ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm() 2018-06-15 07:55:23 +09:00
list_lru.c mm: make counting of list_lru_one::nr_items lockless 2018-04-05 21:36:27 -07:00
maccess.c mm: docs: fix parameter names mismatch 2018-02-06 18:32:48 -08:00
madvise.c mm/memory_failure: Remove unused trapno from memory_failure 2018-01-23 12:17:42 -06:00
Makefile mm: restructure memfd code 2018-06-07 17:34:35 -07:00
memblock.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
memcontrol.c mm: fix oom_kill event handling 2018-06-15 07:55:25 +09:00
memfd.c mm: restructure memfd code 2018-06-07 17:34:35 -07:00
memory_hotplug.c mm: move is_pageblock_removable_nolock() to mm/memory_hotplug.c 2018-06-07 17:34:36 -07:00
memory-failure.c mm, migrate: remove reason argument from new_page_t 2018-04-11 10:28:32 -07:00
memory.c x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings 2018-06-20 19:10:01 +02:00
mempolicy.c mm: unclutter THP migration 2018-04-11 10:28:32 -07:00
mempool.c mempool: Add mempool_init()/mempool_exit() 2018-05-14 13:14:23 -06:00
memtest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
migrate.c mm: migrate: fix double call of radix_tree_replace_slot() 2018-05-11 17:28:45 -07:00
mincore.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mlock.c mm, mlock, vmscan: no more skipping pagevecs 2018-02-21 15:35:42 -08:00
mm_init.c
mmap.c mm: change return type to vm_fault_t 2018-06-07 17:34:36 -07:00
mmu_context.c
mmu_notifier.c mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks 2018-01-31 17:18:38 -08:00
mmzone.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mprotect.c x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings 2018-06-20 19:10:01 +02:00
mremap.c mremap: remove LATENCY_LIMIT from mremap to reduce the number of TLB shootdowns 2018-06-15 07:55:24 +09:00
msync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nobootmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nommu.c mm: use new return type vm_fault_t 2018-06-07 17:34:36 -07:00
oom_kill.c mm: fix oom_kill event handling 2018-06-15 07:55:25 +09:00
page_alloc.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
page_counter.c memcg: introduce memory.min 2018-06-07 17:34:36 -07:00
page_ext.c mm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it 2018-01-31 17:18:39 -08:00
page_idle.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
page_io.c block: convert to bio_first_bvec_all & bio_first_page_all 2018-01-06 09:18:00 -07:00
page_isolation.c mm, migrate: remove reason argument from new_page_t 2018-04-11 10:28:32 -07:00
page_owner.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
page_poison.c mm/page_poison.c: make early_page_poison_param() __init 2018-04-05 21:36:26 -07:00
page_vma_mapped.c mm, page_vma_mapped: Introduce pfn_in_hpage() 2018-01-22 12:15:57 -08:00
page-writeback.c writeback: safer lock nesting 2018-04-20 17:18:35 -07:00
pagewalk.c mm: kernel-doc: add missing parameter descriptions 2018-04-05 21:36:27 -07:00
percpu-internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
percpu-km.c percpu: allow select gfp to be passed to underlying allocators 2018-02-18 05:33:01 -08:00
percpu-stats.c treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
percpu-vm.c percpu: allow select gfp to be passed to underlying allocators 2018-02-18 05:33:01 -08:00
percpu.c arch: remove obsolete architecture ports 2018-04-02 20:20:12 -07:00
pgtable-generic.c mm: do not lose dirty and accessed bits in pmdp_invalidate() 2018-01-31 17:18:38 -08:00
process_vm_access.c mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors 2018-02-06 18:32:48 -08:00
quicklist.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
readahead.c mm: split ->readpages calls to avoid non-contiguous pages lists 2018-06-01 18:37:32 -07:00
rmap.c Linux 4.17-rc2 2018-04-27 17:13:20 -06:00
rodata_test.c
shmem.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
slab_common.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
slab.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
slab.h slab, slub: skip unnecessary kasan_cache_shutdown() 2018-04-05 21:36:24 -07:00
slob.c slab: __GFP_ZERO is incompatible with a constructor 2018-06-07 17:34:34 -07:00
slub.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
sparse-vmemmap.c mm: merge vmem_altmap_alloc into altmap_alloc_block_buf 2018-01-08 11:46:23 -08:00
sparse.c mm/sparse.c: pass the __highest_present_section_nr + 1 to alloc_func() 2018-06-07 17:34:35 -07:00
swap_cgroup.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swap_slots.c treewide: kvzalloc() -> kvcalloc() 2018-06-12 16:19:22 -07:00
swap_state.c treewide: kvzalloc() -> kvcalloc() 2018-06-12 16:19:22 -07:00
swap.c mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS 2018-05-22 06:59:39 -07:00
swapfile.c mm/swapfile.c: fix swap_count comment about nonexistent SWAP_HAS_CONT 2018-06-15 07:55:23 +09:00
truncate.c page cache: use xa_lock 2018-04-11 10:28:39 -07:00
usercopy.c usercopy: WARN() on slab cache usercopy region violations 2018-01-15 12:07:48 -08:00
userfaultfd.c userfaultfd: prevent non-cooperative events vs mcopy_atomic races 2018-06-07 17:34:38 -07:00
util.c mm: kvmalloc does not fallback to vmalloc for incompatible gfp flags 2018-06-07 17:34:38 -07:00
vmacache.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vmalloc.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
vmpressure.c mm/vmpressure.c: convert to use match_string() helper 2018-06-07 17:34:36 -07:00
vmscan.c memcg: introduce memory.min 2018-06-07 17:34:36 -07:00
vmstat.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
workingset.c page cache: use xa_lock 2018-04-11 10:28:39 -07:00
z3fold.c z3fold: fix reclaim lock-ups 2018-05-11 17:28:45 -07:00
zbud.c mm: docs: fix parameter names mismatch 2018-02-06 18:32:48 -08:00
zpool.c mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc 2018-02-21 15:35:43 -08:00
zsmalloc.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
zswap.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00