kasan: disable kasan_non_canonical_hook() for HW tags

On arm64, building with CONFIG_KASAN_HW_TAGS now causes a compile-time
error:

mm/kasan/report.c: In function 'kasan_non_canonical_hook':
mm/kas

kasan: disable kasan_non_canonical_hook() for HW tags

On arm64, building with CONFIG_KASAN_HW_TAGS now causes a compile-time
error:

mm/kasan/report.c: In function 'kasan_non_canonical_hook':
mm/kasan/report.c:637:20: error: 'KASAN_SHADOW_OFFSET' undeclared (first use in this function)
637 | if (addr < KASAN_SHADOW_OFFSET)
| ^~~~~~~~~~~~~~~~~~~
mm/kasan/report.c:637:20: note: each undeclared identifier is reported only once for each function it appears in
mm/kasan/report.c:640:77: error: expected expression before ';' token
640 | orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT;

This was caused by removing the dependency on CONFIG_KASAN_INLINE that
used to prevent this from happening. Use the more specific dependency
on KASAN_SW_TAGS || KASAN_GENERIC to only ignore the function for hwasan
mode.

Link: https://lkml.kernel.org/r/20231016200925.984439-1-arnd@kernel.org
Fixes: 12ec6a919b0f ("kasan: print the original fault addr when access invalid shadow")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Haibo Li <haibo.li@mediatek.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kasan: print the original fault addr when access invalid shadow

when the checked address is illegal,the corresponding shadow address from
kasan_mem_to_shadow may have no mapping in mmu table. Acces

kasan: print the original fault addr when access invalid shadow

when the checked address is illegal,the corresponding shadow address from
kasan_mem_to_shadow may have no mapping in mmu table. Access such shadow
address causes kernel oops. Here is a sample about oops on arm64(VA
39bit) with KASAN_SW_TAGS and KASAN_OUTLINE on:

[ffffffb80aaaaaaa] pgd=000000005d3ce003, p4d=000000005d3ce003,
pud=000000005d3ce003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 3 PID: 100 Comm: sh Not tainted 6.6.0-rc1-dirty #43
Hardware name: linux,dummy-virt (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __hwasan_load8_noabort+0x5c/0x90
lr : do_ib_ob+0xf4/0x110
ffffffb80aaaaaaa is the shadow address for efffff80aaaaaaaa.
The problem is reading invalid shadow in kasan_check_range.

The generic kasan also has similar oops.

It only reports the shadow address which causes oops but not
the original address.

Commit 2f004eea0fc8("x86/kasan: Print original address on #GP")
introduce to kasan_non_canonical_hook but limit it to KASAN_INLINE.

This patch extends it to KASAN_OUTLINE mode.

Link: https://lkml.kernel.org/r/20231009073748.159228-1-haibo.li@mediatek.com
Fixes: 2f004eea0fc8("x86/kasan: Print original address on #GP")
Signed-off-by: Haibo Li <haibo.li@mediatek.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Haibo Li <haibo.li@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kasan: Cleanup the __HAVE_ARCH_SHADOW_MAP usage

As Linus suggested, __HAVE_ARCH_XYZ is "stupid" and "having historical
uses of it doesn't make it good". So migrate __HAVE_ARCH_SHADOW_MAP to
separate

kasan: Cleanup the __HAVE_ARCH_SHADOW_MAP usage

As Linus suggested, __HAVE_ARCH_XYZ is "stupid" and "having historical
uses of it doesn't make it good". So migrate __HAVE_ARCH_SHADOW_MAP to
separate macros named after the respective functions.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

show more ...

kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping

MIPS, LoongArch and some other architectures have many holes between
different segments and the valid address space (256T available

kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping

MIPS, LoongArch and some other architectures have many holes between
different segments and the valid address space (256T available) is
insufficient to map all these segments to kasan shadow memory with the
common formula provided by kasan core. So we need architecture specific
mapping formulas to ensure different segments are mapped individually,
and only limited space lengths of those specific segments are mapped to
shadow.

Therefore, when the incoming address is converted to a shadow, we need
to add a condition to determine whether it is valid.

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

show more ...

kasan: use internal prototypes matching gcc-13 builtins

gcc-13 warns about function definitions for builtin interfaces that have a
different prototype, e.g.:

In file included from kasan_test.c:31:

kasan: use internal prototypes matching gcc-13 builtins

gcc-13 warns about function definitions for builtin interfaces that have a
different prototype, e.g.:

In file included from kasan_test.c:31:
kasan.h:574:6: error: conflicting types for built-in function '__asan_register_globals'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch]
574 | void __asan_register_globals(struct kasan_global *globals, size_t size);
kasan.h:577:6: error: conflicting types for built-in function '__asan_alloca_poison'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch]
577 | void __asan_alloca_poison(unsigned long addr, size_t size);
kasan.h:580:6: error: conflicting types for built-in function '__asan_load1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
580 | void __asan_load1(unsigned long addr);
kasan.h:581:6: error: conflicting types for built-in function '__asan_store1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
581 | void __asan_store1(unsigned long addr);
kasan.h:643:6: error: conflicting types for built-in function '__hwasan_tag_memory'; expected 'void(void *, unsigned char, long int)' [-Werror=builtin-declaration-mismatch]
643 | void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);

The two problems are:

- Addresses are passes as 'unsigned long' in the kernel, but gcc-13
expects a 'void *'.

- sizes meant to use a signed ssize_t rather than size_t.

Change all the prototypes to match these. Using 'void *' consistently for
addresses gets rid of a couple of type casts, so push that down to the
leaf functions where possible.

This now passes all randconfig builds on arm, arm64 and x86, but I have
not tested it on the other architectures that support kasan, since they
tend to fail randconfig builds in other ways. This might fail if any of
the 32-bit architectures expect a 'long' instead of 'int' for the size
argument.

The __asan_allocas_unpoison() function prototype is somewhat weird, since
it uses a pointer for 'stack_top' and an size_t for 'stack_bottom'. This
looks like it is meant to be 'addr' and 'size' like the others, but the
implementation clearly treats them as 'top' and 'bottom'.

Link: https://lkml.kernel.org/r/20230509145735.9263-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

mm/kasan: simplify and refine kasan_cache code

struct 'kasan_cache' has a member 'is_kmalloc' indicating whether its host
kmem_cache is a kmalloc cache. With newly introduced is_kmalloc_cache()
hel

mm/kasan: simplify and refine kasan_cache code

struct 'kasan_cache' has a member 'is_kmalloc' indicating whether its host
kmem_cache is a kmalloc cache. With newly introduced is_kmalloc_cache()
helper, 'is_kmalloc' and its related function can be replaced and removed.

Also 'kasan_cache' is only needed by KASAN generic mode, and not by SW/HW
tag modes, so refine its protection macro accordingly, suggested by Andrey
Konoval.

Link: https://lkml.kernel.org/r/20230104060605.930910-2-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kasan: allow sampling page_alloc allocations for HW_TAGS

As Hardware Tag-Based KASAN is intended to be used in production, its
performance impact is crucial. As page_alloc allocations tend to be bi

kasan: allow sampling page_alloc allocations for HW_TAGS

As Hardware Tag-Based KASAN is intended to be used in production, its
performance impact is crucial. As page_alloc allocations tend to be big,
tagging and checking all such allocations can introduce a significant
slowdown.

Add two new boot parameters that allow to alleviate that slowdown:

- kasan.page_alloc.sample, which makes Hardware Tag-Based KASAN tag only
every Nth page_alloc allocation with the order configured by the second
added parameter (default: tag every such allocation).

- kasan.page_alloc.sample.order, which makes sampling enabled by the first
parameter only affect page_alloc allocations with the order equal or
greater than the specified value (default: 3, see below).

The exact performance improvement caused by using the new parameters
depends on their values and the applied workload.

The chosen default value for kasan.page_alloc.sample.order is 3, which
matches both PAGE_ALLOC_COSTLY_ORDER and SKB_FRAG_PAGE_ORDER. This is
done for two reasons:

1. PAGE_ALLOC_COSTLY_ORDER is "the order at which allocations are deemed
costly to service", which corresponds to the idea that only large and
thus costly allocations are supposed to sampled.

2. One of the workloads targeted by this patch is a benchmark that sends
a large amount of data over a local loopback connection. Most multi-page
data allocations in the networking subsystem have the order of
SKB_FRAG_PAGE_ORDER (or PAGE_ALLOC_COSTLY_ORDER).

When running a local loopback test on a testing MTE-enabled device in sync
mode, enabling Hardware Tag-Based KASAN introduces a ~50% slowdown.
Applying this patch and setting kasan.page_alloc.sampling to a value
higher than 1 allows to lower the slowdown. The performance improvement
saturates around the sampling interval value of 10 with the default
sampling page order of 3. This lowers the slowdown to ~20%. The slowdown
in real scenarios involving the network will likely be better.

Enabling page_alloc sampling has a downside: KASAN misses bad accesses to
a page_alloc allocation that has not been tagged. This lowers the value
of KASAN as a security mitigation.

However, based on measuring the number of page_alloc allocations of
different orders during boot in a test build, sampling with the default
kasan.page_alloc.sample.order value affects only ~7% of allocations. The
rest ~93% of allocations are still checked deterministically.

Link: https://lkml.kernel.org/r/129da0614123bb85ed4dd61ae30842b2dd7c903f.1671471846.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mark Brand <markbrand@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

mm: kasan: Extend kasan_metadata_size() to also cover in-object size

When kasan is enabled for slab/slub, it may save kasan' free_meta
data in the former part of slab object data area in slab object

mm: kasan: Extend kasan_metadata_size() to also cover in-object size

When kasan is enabled for slab/slub, it may save kasan' free_meta
data in the former part of slab object data area in slab object's
free path, which works fine.

There is ongoing effort to extend slub's debug function which will
redzone the latter part of kmalloc object area, and when both of
the debug are enabled, there is possible conflict, especially when
the kmalloc object has small size, as caught by 0Day bot [1].

To solve it, slub code needs to know the in-object kasan's meta
data size. Currently, there is existing kasan_metadata_size()
which returns the kasan's metadata size inside slub's metadata
area, so extend it to also cover the in-object meta size by
adding a boolean flag 'in_object'.

There is no functional change to existing code logic.

[1]. https://lore.kernel.org/lkml/YuYm3dWwpZwH58Hu@xsang-OptiPlex-9020/

Reported-by: kernel test robot <oliver.sang@intel.com>
Suggested-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

show more ...

kasan: only define kasan_cache_create for Generic mode

Right now, kasan_cache_create() assigns SLAB_KASAN for all KASAN modes and
then sets up metadata-related cache parameters for the Generic mode.

kasan: only define kasan_cache_create for Generic mode

Right now, kasan_cache_create() assigns SLAB_KASAN for all KASAN modes and
then sets up metadata-related cache parameters for the Generic mode.

SLAB_KASAN is used in two places:

1. In slab_ksize() to account for per-object metadata when
calculating the size of the accessible memory within the object.
2. In slab_common.c via kasan_never_merge() to prevent merging of
caches with per-object metadata.

Both cases are only relevant when per-object metadata is present, which is
only the case with the Generic mode.

Thus, assign SLAB_KASAN and define kasan_cache_create() only for the
Generic mode.

Also update the SLAB_KASAN-related comment.

Link: https://lkml.kernel.org/r/61faa2aa1906e2d02c97d00ddf99ce8911dda095.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kasan: only define metadata offsets for Generic mode

Hide the definitions of alloc_meta_offset and free_meta_offset under an
ifdef CONFIG_KASAN_GENERIC check, as these fields are now only used when

kasan: only define metadata offsets for Generic mode

Hide the definitions of alloc_meta_offset and free_meta_offset under an
ifdef CONFIG_KASAN_GENERIC check, as these fields are now only used when
the Generic mode is enabled.

Link: https://lkml.kernel.org/r/d4bafa0534facafd1a23c465a94261e64f366493.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kasan: only define kasan_never_merge for Generic mode

KASAN prevents merging of slab caches whose objects have per-object
metadata stored in redzones.

As now only the Generic mode uses per-object m

kasan: only define kasan_never_merge for Generic mode

KASAN prevents merging of slab caches whose objects have per-object
metadata stored in redzones.

As now only the Generic mode uses per-object metadata, define
kasan_never_merge() only for this mode.

Link: https://lkml.kernel.org/r/81ed01f29ff3443580b7e2fe362a8b47b1e8006d.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kasan: only define kasan_metadata_size for Generic mode

KASAN provides a helper for calculating the size of per-object metadata
stored in the redzone.

As now only the Generic mode uses per-object m

kasan: only define kasan_metadata_size for Generic mode

KASAN provides a helper for calculating the size of per-object metadata
stored in the redzone.

As now only the Generic mode uses per-object metadata, only define
kasan_metadata_size() for this mode.

Link: https://lkml.kernel.org/r/8f81d4938b80446bc72538a08217009f328a3e23.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kasan: mark KASAN_VMALLOC flags as kasan_vmalloc_flags_t

Fix sparse warning:

mm/kasan/shadow.c:496:15: warning: restricted kasan_vmalloc_flags_t degrades to integer

Link: https://lkml.kernel.org/r

kasan: mark KASAN_VMALLOC flags as kasan_vmalloc_flags_t

Fix sparse warning:

mm/kasan/shadow.c:496:15: warning: restricted kasan_vmalloc_flags_t degrades to integer

Link: https://lkml.kernel.org/r/52d8fccdd3a48d4bdfd0ff522553bac2a13f1579.1649351254.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kasan: move and hide kasan_save_enable/restore_multi_shot

- Move kasan_save_enable/restore_multi_shot() declarations to
mm/kasan/kasan.h, as there is no need for them to be visible outside
of

kasan: move and hide kasan_save_enable/restore_multi_shot

- Move kasan_save_enable/restore_multi_shot() declarations to
mm/kasan/kasan.h, as there is no need for them to be visible outside
of KASAN implementation.

- Only define and export these functions when KASAN tests are enabled.

- Move their definitions closer to other test-related code in report.c.

Link: https://lkml.kernel.org/r/6ba637333b78447f027d775f2d55ab1a40f63c99.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

kasan: test: support async (again) and asymm modes for HW_TAGS

Async mode support has already been implemented in commit e80a76aa1a91
("kasan, arm64: tests supports for HW_TAGS async mode") but then

kasan: test: support async (again) and asymm modes for HW_TAGS

Async mode support has already been implemented in commit e80a76aa1a91
("kasan, arm64: tests supports for HW_TAGS async mode") but then got
accidentally broken in commit 99734b535d9b ("kasan: detect false-positives
in tests").

Restore the changes removed by the latter patch and adapt them for asymm
mode: add a sync_fault flag to kunit_kasan_expectation that only get set
if the MTE fault was synchronous, and reenable MTE on such faults in
tests.

Also rename kunit_kasan_expectation to kunit_kasan_status and move its
definition to mm/kasan/kasan.h from include/linux/kasan.h, as this
structure is only internally used by KASAN. Also put the structure
definition under IS_ENABLED(CONFIG_KUNIT).

Link: https://lkml.kernel.org/r/133970562ccacc93ba19d754012c562351d4a8c8.1645033139.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

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

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>

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kasan, vmalloc: add vmalloc tagging for HW_TAGS

Add vmalloc tagging support to HW_TAGS KASAN.

The key difference between HW_TAGS and the other two KASAN modes when it
comes to vmalloc: HW_TAGS KASA

kasan, vmalloc: add vmalloc tagging for HW_TAGS

Add vmalloc tagging support to HW_TAGS KASAN.

The key difference between HW_TAGS and the other two KASAN modes when it
comes to vmalloc: HW_TAGS KASAN can only assign tags to physical memory.
The other two modes have shadow memory covering every mapped virtual
memory region.

Make __kasan_unpoison_vmalloc() for HW_TAGS KASAN:

- Skip non-VM_ALLOC mappings as HW_TAGS KASAN can only tag a single
mapping of normal physical memory; see the comment in the function.

- Generate a random tag, tag the returned pointer and the allocation,
and initialize the allocation at the same time.

- Propagate the tag into the page stucts to allow accesses through
page_address(vmalloc_to_page()).

The rest of vmalloc-related KASAN hooks are not needed:

- The shadow-related ones are fully skipped.

- __kasan_poison_vmalloc() is kept as a no-op with a comment.

Poisoning and zeroing of physical pages that are backing vmalloc()
allocations are skipped via __GFP_SKIP_KASAN_UNPOISON and
__GFP_SKIP_ZERO: __kasan_unpoison_vmalloc() does that instead.

Enabling CONFIG_KASAN_VMALLOC with HW_TAGS is not yet allowed.

Link: https://lkml.kernel.org/r/d19b2e9e59a9abc59d05b72dea8429dcaea739c6.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.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: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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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 accordin

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>

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kasan: add wrappers for vmalloc hooks

Add wrappers around functions that [un]poison memory for vmalloc
allocations. These functions will be used by HW_TAGS KASAN and therefore
need to be disabled w

kasan: add wrappers for vmalloc hooks

Add wrappers around functions that [un]poison memory for vmalloc
allocations. These functions will be used by HW_TAGS KASAN and therefore
need to be disabled when kasan=off command line argument is provided.

This patch does no functional changes for software KASAN modes.

Link: https://lkml.kernel.org/r/3b8728eac438c55389fb0f9a8a2145d71dd77487.1643047180.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>

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kasan: reorder vmalloc hooks

Group functions that [de]populate shadow memory for vmalloc. Group
functions that [un]poison memory for vmalloc.

This patch does no functional changes but prepares KAS

kasan: reorder vmalloc hooks

Group functions that [de]populate shadow memory for vmalloc. Group
functions that [un]poison memory for vmalloc.

This patch does no functional changes but prepares KASAN code for adding
vmalloc support to HW_TAGS KASAN.

Link: https://lkml.kernel.org/r/aeef49eb249c206c4c9acce2437728068da74c28.1643047180.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>

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kasan, x86, arm64, s390: rename functions for modules shadow

Rename kasan_free_shadow to kasan_free_module_shadow and
kasan_module_alloc to kasan_alloc_module_shadow.

These functions are used to al

kasan, x86, arm64, s390: rename functions for modules shadow

Rename kasan_free_shadow to kasan_free_module_shadow and
kasan_module_alloc to kasan_alloc_module_shadow.

These functions are used to allocate/free shadow memory for kernel modules
when KASAN_VMALLOC is not enabled. The new names better reflect their
purpose.

Also reword the comment next to their declaration to improve clarity.

Link: https://lkml.kernel.org/r/36db32bde765d5d0b856f77d2d806e838513fe84.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.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>

show more ...

kasan, page_alloc: merge kasan_alloc_pages into post_alloc_hook

Currently, the code responsible for initializing and poisoning memory in
post_alloc_hook() is scattered across two locations: kasan_al

kasan, page_alloc: merge kasan_alloc_pages into post_alloc_hook

Currently, the code responsible for initializing and poisoning memory in
post_alloc_hook() is scattered across two locations: kasan_alloc_pages()
hook for HW_TAGS KASAN and post_alloc_hook() itself. This is confusing.

This and a few following patches combine the code from these two
locations. Along the way, these patches do a step-by-step restructure the
many performed checks to make them easier to follow.

Replace the only caller of kasan_alloc_pages() with its implementation.

As kasan_has_integrated_init() is only true when CONFIG_KASAN_HW_TAGS is
enabled, moving the code does no functional changes.

Also move init and init_tags variables definitions out of
kasan_has_integrated_init() clause in post_alloc_hook(), as they have the
same values regardless of what the if condition evaluates to.

This patch is not useful by itself but makes the simplifications in the
following patches easier to follow.

Link: https://lkml.kernel.org/r/5ac7e0b30f5cbb177ec363ddd7878a3141289592.1643047180.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>

show more ...

kasan, page_alloc: merge kasan_free_pages into free_pages_prepare

Currently, the code responsible for initializing and poisoning memory in
free_pages_prepare() is scattered across two locations: kas

kasan, page_alloc: merge kasan_free_pages into free_pages_prepare

Currently, the code responsible for initializing and poisoning memory in
free_pages_prepare() is scattered across two locations: kasan_free_pages()
for HW_TAGS KASAN and free_pages_prepare() itself. This is confusing.

This and a few following patches combine the code from these two
locations. Along the way, these patches also simplify the performed
checks to make them easier to follow.

Replaces the only caller of kasan_free_pages() with its implementation.

As kasan_has_integrated_init() is only true when CONFIG_KASAN_HW_TAGS is
enabled, moving the code does no functional changes.

This patch is not useful by itself but makes the simplifications in the
following patches easier to follow.

Link: https://lkml.kernel.org/r/303498d15840bb71905852955c6e2390ecc87139.1643047180.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>

show more ...

kasan: split kasan_*enabled() functions into a separate header

In an upcoming commit we are going to need to call
kasan_hw_tags_enabled() from arch/arm64/include/asm/mte.h. This
would create a circu

kasan: split kasan_*enabled() functions into a separate header

In an upcoming commit we are going to need to call
kasan_hw_tags_enabled() from arch/arm64/include/asm/mte.h. This
would create a circular dependency between headers if KASAN_GENERIC
or KASAN_SW_TAGS is enabled: linux/kasan.h -> linux/pgtable.h ->
asm/pgtable.h -> asm/mte.h -> linux/kasan.h. Break the cycle
by introducing a new header linux/kasan-enabled.h with the
kasan_*enabled() functions that can be included from asm/mte.h.

Link: https://linux-review.googlesource.com/id/I5b0d96c6ed0026fc790899e14d42b2fac6ab568e
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20220219012945.894950-1-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>

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mm: defer kmemleak object creation of module_alloc()

Yongqiang reports a kmemleak panic when module insmod/rmmod with KASAN
enabled(without KASAN_VMALLOC) on x86[1].

When the module area allocates

mm: defer kmemleak object creation of module_alloc()

Yongqiang reports a kmemleak panic when module insmod/rmmod with KASAN
enabled(without KASAN_VMALLOC) on x86[1].

When the module area allocates memory, it's kmemleak_object is created
successfully, but the KASAN shadow memory of module allocation is not
ready, so when kmemleak scan the module's pointer, it will panic due to
no shadow memory with KASAN check.

module_alloc
__vmalloc_node_range
kmemleak_vmalloc
kmemleak_scan
update_checksum
kasan_module_alloc
kmemleak_ignore

Note, there is no problem if KASAN_VMALLOC enabled, the modules area
entire shadow memory is preallocated. Thus, the bug only exits on ARCH
which supports dynamic allocation of module area per module load, for
now, only x86/arm64/s390 are involved.

Add a VM_DEFER_KMEMLEAK flags, defer vmalloc'ed object register of
kmemleak in module_alloc() to fix this issue.

[1] https://lore.kernel.org/all/6d41e2b9-4692-5ec4-b1cd-cbe29ae89739@huawei.com/

[wangkefeng.wang@huawei.com: fix build]
Link: https://lkml.kernel.org/r/20211125080307.27225-1-wangkefeng.wang@huawei.com
[akpm@linux-foundation.org: simplify ifdefs, per Andrey]
Link: https://lkml.kernel.org/r/CA+fCnZcnwJHUQq34VuRxpdoY6_XbJCDJ-jopksS5Eia4PijPzw@mail.gmail.com

Link: https://lkml.kernel.org/r/20211124142034.192078-1-wangkefeng.wang@huawei.com
Fixes: 793213a82de4 ("s390/kasan: dynamic shadow mem allocation for modules")
Fixes: 39d114ddc682 ("arm64: add KASAN support")
Fixes: bebf56a1b176 ("kasan: enable instrumentation of global variables")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reported-by: Yongqiang Liu <liuyongqiang13@huawei.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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