kernel_optimize_test/mm
Andrey Ryabinin 00fb24a42a mm/kasan: fix false positive invalid-free reports with CONFIG_KASAN_SW_TAGS=y
The code like this:

	ptr = kmalloc(size, GFP_KERNEL);
	page = virt_to_page(ptr);
	offset = offset_in_page(ptr);
	kfree(page_address(page) + offset);

may produce false-positive invalid-free reports on the kernel with
CONFIG_KASAN_SW_TAGS=y.

In the example above we lose the original tag assigned to 'ptr', so
kfree() gets the pointer with 0xFF tag.  In kfree() we check that 0xFF
tag is different from the tag in shadow hence print false report.

Instead of just comparing tags, do the following:

1) Check that shadow doesn't contain KASAN_TAG_INVALID.  Otherwise it's
   double-free and it doesn't matter what tag the pointer have.

2) If pointer tag is different from 0xFF, make sure that tag in the
   shadow is the same as in the pointer.

Link: http://lkml.kernel.org/r/20190819172540.19581-1-aryabinin@virtuozzo.com
Fixes: 7f94ffbc4c ("kasan: add hooks implementation for tag-based mode")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Walter Wu <walter-zh.wu@mediatek.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-24 19:48:42 -07:00
..
kasan mm/kasan: fix false positive invalid-free reports with CONFIG_KASAN_SW_TAGS=y 2019-08-24 19:48:42 -07:00
backing-dev.c
balloon_compaction.c balloon: fix up comments 2019-07-22 11:19:26 -04:00
cleancache.c
cma_debug.c
cma.c
cma.h
compaction.c mm: compaction: avoid 100% CPU usage during compaction when a task is killed 2019-08-03 07:02:00 -07:00
debug_page_ref.c
debug.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c
frame_vector.c
frontswap.c
gup_benchmark.c
gup.c
highmem.c
hmm.c mm/hmm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot} 2019-07-25 16:14:39 -03:00
huge_memory.c mm, page_owner: handle THP splits correctly 2019-08-24 19:48:42 -07:00
hugetlb_cgroup.c
hugetlb.c hugetlbfs: fix hugetlb page migration/fault race causing SIGBUS 2019-08-13 16:06:53 -07:00
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
Kconfig
Kconfig.debug
khugepaged.c
kmemleak-test.c
kmemleak.c mm: kmemleak: disable early logging in case of error 2019-08-13 16:06:52 -07:00
ksm.c
list_lru.c
maccess.c
madvise.c
Makefile memremap: move from kernel/ to mm/ 2019-08-03 07:02:01 -07:00
memblock.c
memcontrol.c mm: memcontrol: flush percpu vmevents before releasing memcg 2019-08-24 19:48:42 -07:00
memfd.c
memory_hotplug.c mm/memory_hotplug.c: remove unneeded return for void function 2019-08-03 07:02:01 -07:00
memory-failure.c
memory.c
mempolicy.c Revert "mm, thp: restore node-local hugepage allocations" 2019-08-13 16:06:52 -07:00
mempool.c
memremap.c mm/hmm: fix ZONE_DEVICE anon page mapping reuse 2019-08-13 16:06:52 -07:00
memtest.c
migrate.c mm/migrate.c: initialize pud_entry in migrate_vma() 2019-08-03 07:02:01 -07:00
mincore.c
mlock.c
mm_init.c
mmap.c
mmu_context.c
mmu_gather.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nommu.c
oom_kill.c
page_alloc.c mm, page_alloc: move_freepages should not examine struct page of reserved memory 2019-08-24 19:48:42 -07:00
page_counter.c
page_ext.c
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page_poison.c
page_vma_mapped.c
page-writeback.c
pagewalk.c
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c
rmap.c mm/hmm: fix bad subpage pointer in try_to_unmap_one 2019-08-13 16:06:52 -07:00
rodata_test.c
shmem.c Revert "Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask"" 2019-08-13 16:06:52 -07:00
shuffle.c
shuffle.h
slab_common.c
slab.c
slab.h
slob.c
slub.c mm: slub: Fix slab walking for init_on_free 2019-07-31 13:16:06 -07:00
sparse-vmemmap.c
sparse.c
swap_cgroup.c
swap_slots.c
swap_state.c
swap.c
swapfile.c
truncate.c
usercopy.c mm/usercopy: use memory range to be accessed for wraparound check 2019-08-13 16:06:52 -07:00
userfaultfd.c
util.c
vmacache.c
vmalloc.c mm/vmalloc.c: fix percpu free VM area search criteria 2019-08-13 16:06:52 -07:00
vmpressure.c
vmscan.c mm, vmscan: do not special-case slab reclaim when watermarks are boosted 2019-08-13 16:06:53 -07:00
vmstat.c
workingset.c mm: workingset: fix vmstat counters for shadow nodes 2019-08-13 16:06:52 -07:00
z3fold.c mm/z3fold.c: fix race between migration and destruction 2019-08-24 19:48:42 -07:00
zbud.c
zpool.c
zsmalloc.c mm/zsmalloc.c: fix race condition in zs_destroy_pool 2019-08-24 19:48:42 -07:00
zswap.c