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linux-stable/mm/kasan
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Lecopzer Chen ecd63f04e7 kasan: fix unaligned address is unhandled in kasan_remove_zero_shadow 
commit a11a496ee6 upstream.

During testing kasan_populate_early_shadow and kasan_remove_zero_shadow,
if the shadow start and end address in kasan_remove_zero_shadow() is not
aligned to PMD_SIZE, the remain unaligned PTE won't be removed.

In the test case for kasan_remove_zero_shadow():

    shadow_start: 0xffffffb802000000, shadow end: 0xffffffbfbe000000

    3-level page table:
      PUD_SIZE: 0x40000000 PMD_SIZE: 0x200000 PAGE_SIZE: 4K

0xffffffbf80000000 ~ 0xffffffbfbdf80000 will not be removed because in
kasan_remove_pud_table(), kasan_pmd_table(*pud) is true but the next
address is 0xffffffbfbdf80000 which is not aligned to PUD_SIZE.

In the correct condition, this should fallback to the next level
kasan_remove_pmd_table() but the condition flow always continue to skip
the unaligned part.

Fix by correcting the condition when next and addr are neither aligned.

Link: https://lkml.kernel.org/r/20210103135621.83129-1-lecopzer@gmail.com
Fixes: 0207df4fa1 ("kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN")
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:55:23 +01:00
..
common.c kasan: remove kasan_unpoison_stack_above_sp_to() 2020-08-07 11:33:28 -07:00
generic.c kasan: record and print the free track 2020-08-07 11:33:28 -07:00
generic_report.c kasan: record and print the free track 2020-08-07 11:33:28 -07:00
init.c kasan: fix unaligned address is unhandled in kasan_remove_zero_shadow 2021-01-27 11:55:23 +01:00
kasan.h kasan: record and print the free track 2020-08-07 11:33:28 -07:00
Makefile kbuild: remove cc-option test of -fno-stack-protector 2020-07-07 11:13:10 +09:00
quarantine.c kasan: fix object remaining in offline per-cpu quarantine 2020-12-11 14:02:14 -08:00
report.c mm: kasan: do not panic if both panic_on_warn and kasan_multishot set 2020-10-13 18:38:32 -07:00
tags.c kasan: record and print the free track 2020-08-07 11:33:28 -07:00
tags_report.c kasan: detect negative size in memory operation function 2020-04-02 09:35:30 -07:00