From: andrey.konovalov@linux.dev
To: Marco Elver <elver@google.com>,
Alexander Potapenko <glider@google.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
linux-arm-kernel@lists.infradead.org,
Peter Collingbourne <pcc@google.com>,
Evgenii Stepanov <eugenis@google.com>,
linux-kernel@vger.kernel.org,
Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH mm v4 32/39] kasan, arm64: don't tag executable vmalloc allocations
Date: Mon, 20 Dec 2021 23:02:04 +0100 [thread overview]
Message-ID: <85ecef50788a3915a9a8fb52e97207901f27b057.1640036051.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1640036051.git.andreyknvl@google.com>
From: Andrey Konovalov <andreyknvl@google.com>
Besides asking vmalloc memory to be executable via the prot argument
of __vmalloc_node_range() (see the previous patch), the kernel can skip
that bit and instead mark memory as executable via set_memory_x().
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.
Generic kernel code typically allocates memory via module_alloc() if
it intends to mark memory as executable. (On arm64 module_alloc()
uses __vmalloc_node_range() without setting the executable bit).
Thus, reset pointer tags of pointers returned from module_alloc().
However, on arm64 there's an exception: the eBPF subsystem. Instead of
using module_alloc(), it uses vmalloc() (via bpf_jit_alloc_exec())
to allocate its JIT region.
Thus, reset pointer tags of pointers returned from bpf_jit_alloc_exec().
Resetting tags for these pointers results in untagged pointers being
passed to set_memory_x(). This causes conflicts in arithmetic checks
in change_memory_common(), as vm_struct->addr pointer returned by
find_vm_area() is tagged.
Reset pointer tag of find_vm_area(addr)->addr in change_memory_common().
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
Changes v3->v4:
- Reset pointer tag in change_memory_common().
Changes v2->v3:
- Add this patch.
---
arch/arm64/kernel/module.c | 3 ++-
arch/arm64/mm/pageattr.c | 2 +-
arch/arm64/net/bpf_jit_comp.c | 3 ++-
3 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index d3a1fa818348..f2d4bb14bfab 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -63,7 +63,8 @@ void *module_alloc(unsigned long size)
return NULL;
}
- return p;
+ /* Memory is intended to be executable, reset the pointer tag. */
+ return kasan_reset_tag(p);
}
enum aarch64_reloc_op {
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index a3bacd79507a..64e985eaa52d 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -85,7 +85,7 @@ static int change_memory_common(unsigned long addr, int numpages,
*/
area = find_vm_area((void *)addr);
if (!area ||
- end > (unsigned long)area->addr + area->size ||
+ end > (unsigned long)kasan_reset_tag(area->addr) + area->size ||
!(area->flags & VM_ALLOC))
return -EINVAL;
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 07aad85848fa..381a67922c2d 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -1147,7 +1147,8 @@ u64 bpf_jit_alloc_exec_limit(void)
void *bpf_jit_alloc_exec(unsigned long size)
{
- return vmalloc(size);
+ /* Memory is intended to be executable, reset the pointer tag. */
+ return kasan_reset_tag(vmalloc(size));
}
void bpf_jit_free_exec(void *addr)
--
2.25.1
next prev parent reply other threads:[~2021-12-20 22:02 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-20 21:58 [PATCH mm v4 00/39] kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 01/39] kasan, page_alloc: deduplicate should_skip_kasan_poison andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 02/39] kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 03/39] kasan, page_alloc: merge kasan_free_pages into free_pages_prepare andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 04/39] kasan, page_alloc: simplify kasan_poison_pages call site andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 05/39] kasan, page_alloc: init memory of skipped pages on free andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 06/39] kasan: drop skip_kasan_poison variable in free_pages_prepare andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 07/39] mm: clarify __GFP_ZEROTAGS comment andrey.konovalov
2021-12-21 9:16 ` Alexander Potapenko
2021-12-30 19:11 ` Andrey Konovalov
2021-12-20 21:58 ` [PATCH mm v4 08/39] kasan: only apply __GFP_ZEROTAGS when memory is zeroed andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 09/39] kasan, page_alloc: refactor init checks in post_alloc_hook andrey.konovalov
2021-12-20 21:58 ` [PATCH mm v4 10/39] kasan, page_alloc: merge kasan_alloc_pages into post_alloc_hook andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 11/39] kasan, page_alloc: combine tag_clear_highpage calls in post_alloc_hook andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 12/39] kasan, page_alloc: move SetPageSkipKASanPoison " andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 13/39] kasan, page_alloc: move kernel_init_free_pages " andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 14/39] kasan, page_alloc: rework kasan_unpoison_pages call site andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 15/39] kasan: clean up metadata byte definitions andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 16/39] kasan: define KASAN_VMALLOC_INVALID for SW_TAGS andrey.konovalov
2021-12-21 9:23 ` Alexander Potapenko
2021-12-20 21:59 ` [PATCH mm v4 17/39] kasan, x86, arm64, s390: rename functions for modules shadow andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 18/39] kasan, vmalloc: drop outdated VM_KASAN comment andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 19/39] kasan: reorder vmalloc hooks andrey.konovalov
2021-12-20 21:59 ` [PATCH mm v4 20/39] kasan: add wrappers for " andrey.konovalov
2021-12-21 14:21 ` Alexander Potapenko
2021-12-20 21:59 ` [PATCH mm v4 21/39] kasan, vmalloc: reset tags in vmalloc functions andrey.konovalov
2021-12-20 22:01 ` [PATCH mm v4 22/39] kasan, fork: reset pointer tags of vmapped stacks andrey.konovalov
2021-12-21 15:11 ` Alexander Potapenko
2021-12-20 22:01 ` [PATCH mm v4 23/39] kasan, arm64: " andrey.konovalov
2021-12-20 22:01 ` [PATCH mm v4 24/39] kasan, vmalloc: add vmalloc tagging for SW_TAGS andrey.konovalov
2021-12-20 22:01 ` [PATCH mm v4 25/39] kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged andrey.konovalov
2021-12-20 22:01 ` [PATCH mm v4 26/39] kasan, vmalloc: unpoison VM_ALLOC pages after mapping andrey.konovalov
2021-12-21 11:50 ` Alexander Potapenko
2021-12-20 22:01 ` [PATCH mm v4 27/39] kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS andrey.konovalov
2021-12-20 22:02 ` [PATCH mm v4 28/39] kasan, page_alloc: allow skipping unpoisoning for HW_TAGS andrey.konovalov
2021-12-21 12:04 ` Marco Elver
2021-12-30 19:11 ` Andrey Konovalov
2021-12-21 12:14 ` Marco Elver
2021-12-21 12:19 ` Marco Elver
2021-12-20 22:02 ` [PATCH mm v4 29/39] kasan, page_alloc: allow skipping memory init " andrey.konovalov
2021-12-21 12:11 ` Marco Elver
2021-12-30 19:11 ` Andrey Konovalov
2021-12-21 12:30 ` Marco Elver
2021-12-30 19:11 ` Andrey Konovalov
2021-12-20 22:02 ` [PATCH mm v4 30/39] kasan, vmalloc: add vmalloc tagging " andrey.konovalov
2021-12-20 22:02 ` [PATCH mm v4 31/39] kasan, vmalloc: only tag normal vmalloc allocations andrey.konovalov
2021-12-20 22:02 ` andrey.konovalov [this message]
2021-12-20 22:05 ` [PATCH mm v4 32/39] kasan, arm64: don't tag executable " Andrey Konovalov
2021-12-22 11:11 ` Catalin Marinas
2021-12-20 22:02 ` [PATCH mm v4 33/39] kasan: mark kasan_arg_stacktrace as __initdata andrey.konovalov
2021-12-20 22:02 ` [PATCH mm v4 34/39] kasan: simplify kasan_init_hw_tags andrey.konovalov
2021-12-20 22:02 ` [PATCH mm v4 35/39] kasan: add kasan.vmalloc command line flag andrey.konovalov
2021-12-21 14:43 ` Alexander Potapenko
2021-12-30 19:11 ` Andrey Konovalov
2021-12-20 22:03 ` [PATCH mm v4 36/39] kasan: allow enabling KASAN_VMALLOC and SW/HW_TAGS andrey.konovalov
2021-12-20 22:03 ` [PATCH mm v4 37/39] arm64: select KASAN_VMALLOC for SW/HW_TAGS modes andrey.konovalov
2021-12-20 22:03 ` [PATCH mm v4 38/39] kasan: documentation updates andrey.konovalov
2021-12-20 22:03 ` [PATCH mm v4 39/39] kasan: improve vmalloc tests andrey.konovalov
2021-12-22 7:00 ` [PATCH mm v4 00/39] kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS Marco Elver
2021-12-30 19:11 ` Andrey Konovalov
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