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authorAndrey Konovalov <andreyknvl@google.com>2022-03-24 18:11:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-24 19:06:47 -0700
commit1d96320f8d5320423737da61e6e6937f6b475b5c (patch)
treec02b81a956f55c6b9324fb0861b75f31cf9b8984 /mm/kasan
parent51fb34de2a4c8fa0f221246313700bfe3b6c586d (diff)
kasan, vmalloc: add vmalloc tagging for SW_TAGS
Add vmalloc tagging support to SW_TAGS KASAN. - __kasan_unpoison_vmalloc() now assigns a random pointer tag, poisons the virtual mapping accordingly, and embeds the tag into the returned pointer. - __get_vm_area_node() (used by vmalloc() and vmap()) and pcpu_get_vm_areas() save the tagged pointer into vm_struct->addr (note: not into vmap_area->addr). This requires putting kasan_unpoison_vmalloc() after setup_vmalloc_vm[_locked](); otherwise the latter will overwrite the tagged pointer. The tagged pointer then is naturally propagateed to vmalloc() and vmap(). - vm_map_ram() returns the tagged pointer directly. As a result of this change, vm_struct->addr is now tagged. Enabling KASAN_VMALLOC with SW_TAGS is not yet allowed. Link: https://lkml.kernel.org/r/4a78f3c064ce905e9070c29733aca1dd254a74f1.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan')
-rw-r--r--mm/kasan/shadow.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index 39d0b32ebf70..5a866f6663fc 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -475,12 +475,14 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end,
}
}
-void __kasan_unpoison_vmalloc(const void *start, unsigned long size)
+void *__kasan_unpoison_vmalloc(const void *start, unsigned long size)
{
if (!is_vmalloc_or_module_addr(start))
- return;
+ return (void *)start;
+ start = set_tag(start, kasan_random_tag());
kasan_unpoison(start, size, false);
+ return (void *)start;
}
/*