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| author | Andrey Konovalov <andreyknvl@google.com> | 2022-03-25 02:11:07 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-25 03:06:47 +0100 |
| commit | c08e6a1206e6876c66e0528b3ec717f557b07dd4 (patch) | |
| tree | 9bf2542aa5b5593c990cef53c0e626c91be468bc /kernel/fork.c | |
| parent | kasan, vmalloc: reset tags in vmalloc functions (diff) | |
| download | linux-c08e6a1206e6876c66e0528b3ec717f557b07dd4.tar.xz linux-c08e6a1206e6876c66e0528b3ec717f557b07dd4.zip | |
kasan, fork: reset pointer tags of vmapped stacks
Once tag-based KASAN modes start tagging vmalloc() allocations, kernel
stacks start getting tagged if CONFIG_VMAP_STACK is enabled.
Reset the tag of kernel stack pointers after allocation in
alloc_thread_stack_node().
For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the instrumentation
can't handle the SP register being tagged.
For HW_TAGS KASAN, there's no instrumentation-related issues. However,
the impact of having a tagged SP register needs to be properly evaluated,
so keep it non-tagged for now.
Note, that the memory for the stack allocation still gets tagged to catch
vmalloc-into-stack out-of-bounds accesses.
Link: https://lkml.kernel.org/r/c6c96f012371ecd80e1936509ebcd3b07a5956f7.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@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 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 834af51ed397..ce0ffe48937f 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -326,6 +326,8 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node) * so cache the vm_struct. */ tsk->stack_vm_area = vm; + if (stack) + stack = kasan_reset_tag(stack); tsk->stack = stack; return 0; } |