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| author | Andrey Konovalov <andreyknvl@google.com> | 2020-08-07 08:24:57 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 20:33:28 +0200 |
| commit | 8dcc1d34661d58a7889fb06517c8738d1412d1bc (patch) | |
| tree | 2182e336ca1f7ec2a01f21c3a6daf06373a15fcb | |
| parent | lib/test_kasan.c: fix KASAN unit tests for tag-based KASAN (diff) | |
| download | linux-8dcc1d34661d58a7889fb06517c8738d1412d1bc.tar.xz linux-8dcc1d34661d58a7889fb06517c8738d1412d1bc.zip | |
kasan: don't tag stacks allocated with pagealloc
Patch series "kasan: support stack instrumentation for tag-based mode", v2.
This patch (of 5):
Prepare Software Tag-Based KASAN for stack tagging support.
With Tag-Based KASAN when kernel stacks are allocated via pagealloc (which
happens when CONFIG_VMAP_STACK is not enabled), they get tagged. KASAN
instrumentation doesn't expect the sp register to be tagged, and this
leads to false-positive reports.
Fix by resetting the tag of kernel stack pointers after allocation.
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: http://lkml.kernel.org/r/cover.1596199677.git.andreyknvl@google.com
Link: http://lkml.kernel.org/r/cover.1596544734.git.andreyknvl@google.com
Link: http://lkml.kernel.org/r/12d8c678869268dd0884b01271ab592f30792abf.1596544734.git.andreyknvl@google.com
Link: http://lkml.kernel.org/r/01c678b877755bcf29009176592402cdf6f2cb15.1596199677.git.andreyknvl@google.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203497
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/fork.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index c7b4ce9d2647..35e9894d394c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -261,7 +261,7 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) THREAD_SIZE_ORDER); if (likely(page)) { - tsk->stack = page_address(page); + tsk->stack = kasan_reset_tag(page_address(page)); return tsk->stack; } return NULL; @@ -302,6 +302,7 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, { unsigned long *stack; stack = kmem_cache_alloc_node(thread_stack_cache, THREADINFO_GFP, node); + stack = kasan_reset_tag(stack); tsk->stack = stack; return stack; } |