diff options
| author | Andrey Konovalov <andreyknvl@google.com> | 2022-03-24 18:11:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-24 19:06:48 -0700 |
| commit | f6e39794f4b6da7ca9b77f2f9ad11fd6f0ac83e5 (patch) | |
| tree | c057cf61a7e7e14b2b64d7f4e020ac297f6b46ae /kernel | |
| parent | 23689e91fb22c15b84ac6c22ad9942039792f3af (diff) | |
kasan, vmalloc: only tag normal vmalloc allocations
The kernel can use to allocate executable memory. The only supported
way to do that is via __vmalloc_node_range() with the executable bit set
in the prot argument. (vmap() resets the bit via pgprot_nx()).
Once tag-based KASAN modes start tagging vmalloc allocations, executing
code from such allocations will lead to the PC register getting a tag,
which is not tolerated by the kernel.
Only tag the allocations for normal kernel pages.
[andreyknvl@google.com: pass KASAN_VMALLOC_PROT_NORMAL to kasan_unpoison_vmalloc()]
Link: https://lkml.kernel.org/r/9230ca3d3e40ffca041c133a524191fd71969a8d.1646233925.git.andreyknvl@google.com
[andreyknvl@google.com: support tagged vmalloc mappings]
Link: https://lkml.kernel.org/r/2f6605e3a358cf64d73a05710cb3da356886ad29.1646233925.git.andreyknvl@google.com
[andreyknvl@google.com: don't unintentionally disabled poisoning]
Link: https://lkml.kernel.org/r/de4587d6a719232e83c760113e46ed2d4d8da61e.1646757322.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/fbfd9939a4dc375923c9a5c6b9e7ab05c26b8c6b.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 'kernel')
| -rw-r--r-- | kernel/scs.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/kernel/scs.c b/kernel/scs.c index b83bc9251f99..b7e1b096d906 100644 --- a/kernel/scs.c +++ b/kernel/scs.c @@ -32,15 +32,19 @@ static void *__scs_alloc(int node) for (i = 0; i < NR_CACHED_SCS; i++) { s = this_cpu_xchg(scs_cache[i], NULL); if (s) { - kasan_unpoison_vmalloc(s, SCS_SIZE, KASAN_VMALLOC_NONE); + s = kasan_unpoison_vmalloc(s, SCS_SIZE, + KASAN_VMALLOC_PROT_NORMAL); memset(s, 0, SCS_SIZE); - return s; + goto out; } } - return __vmalloc_node_range(SCS_SIZE, 1, VMALLOC_START, VMALLOC_END, + s = __vmalloc_node_range(SCS_SIZE, 1, VMALLOC_START, VMALLOC_END, GFP_SCS, PAGE_KERNEL, 0, node, __builtin_return_address(0)); + +out: + return kasan_reset_tag(s); } void *scs_alloc(int node) @@ -78,7 +82,7 @@ void scs_free(void *s) if (this_cpu_cmpxchg(scs_cache[i], 0, s) == NULL) return; - kasan_unpoison_vmalloc(s, SCS_SIZE, KASAN_VMALLOC_NONE); + kasan_unpoison_vmalloc(s, SCS_SIZE, KASAN_VMALLOC_PROT_NORMAL); vfree_atomic(s); } |