kasan, mm: fix resetting page_alloc tags for HW_TAGS

A previous commit added resetting KASAN page tags to
kernel_init_free_pages() to avoid false-positives due to accesses to
metadata with the hardware tag-based mode.

That commit did reset page tags before the metadata access, but didn't
restore them after.  As the result, KASAN fails to detect bad accesses
to page_alloc allocations on some configurations.

Fix this by recovering the tag after the metadata access.

Link: https://lkml.kernel.org/r/02b5bcd692e912c27d484030f666b350ad7e4ae4.1611074450.git.andreyknvl@google.com
Fixes: aa1ef4d7b3f6 ("kasan, mm: reset tags when accessing metadata")
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Branislav Rankov <[email protected]>
Cc: Kevin Brodsky <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions