The patch titled
Subject: kasan: hw_tags: avoid invalid virt_to_page()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
kasan-hw_tags-avoid-invalid-virt_to_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Mark Rutland <mark.rutland(a)arm.com>
Subject: kasan: hw_tags: avoid invalid virt_to_page()
Date: Tue, 18 Apr 2023 17:42:12 +0100
When booting with 'kasan.vmalloc=off', a kernel configured with support
for KASAN_HW_TAGS will explode at boot time due to bogus use of
virt_to_page() on a vmalloc adddress. With CONFIG_DEBUG_VIRTUAL selected
this will be reported explicitly, and with or without CONFIG_DEBUG_VIRTUAL
the kernel will dereference a bogus address:
| ------------[ cut here ]------------
| virt_to_phys used for non-linear address: (____ptrval____) (0xffff800008000000)
| WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x78/0x80
| Modules linked in:
| CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.3.0-rc3-00073-g83865133300d-dirty #4
| Hardware name: linux,dummy-virt (DT)
| pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : __virt_to_phys+0x78/0x80
| lr : __virt_to_phys+0x78/0x80
| sp : ffffcd076afd3c80
| x29: ffffcd076afd3c80 x28: 0068000000000f07 x27: ffff800008000000
| x26: fffffbfff0000000 x25: fffffbffff000000 x24: ff00000000000000
| x23: ffffcd076ad3c000 x22: fffffc0000000000 x21: ffff800008000000
| x20: ffff800008004000 x19: ffff800008000000 x18: ffff800008004000
| x17: 666678302820295f x16: ffffffffffffffff x15: 0000000000000004
| x14: ffffcd076b009e88 x13: 0000000000000fff x12: 0000000000000003
| x11: 00000000ffffefff x10: c0000000ffffefff x9 : 0000000000000000
| x8 : 0000000000000000 x7 : 205d303030303030 x6 : 302e30202020205b
| x5 : ffffcd076b41d63f x4 : ffffcd076afd3827 x3 : 0000000000000000
| x2 : 0000000000000000 x1 : ffffcd076afd3a30 x0 : 000000000000004f
| Call trace:
| __virt_to_phys+0x78/0x80
| __kasan_unpoison_vmalloc+0xd4/0x478
| __vmalloc_node_range+0x77c/0x7b8
| __vmalloc_node+0x54/0x64
| init_IRQ+0x94/0xc8
| start_kernel+0x194/0x420
| __primary_switched+0xbc/0xc4
| ---[ end trace 0000000000000000 ]---
| Unable to handle kernel paging request at virtual address 03fffacbe27b8000
| Mem abort info:
| ESR = 0x0000000096000004
| EC = 0x25: DABT (current EL), IL = 32 bits
| SET = 0, FnV = 0
| EA = 0, S1PTW = 0
| FSC = 0x04: level 0 translation fault
| Data abort info:
| ISV = 0, ISS = 0x00000004
| CM = 0, WnR = 0
| swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000041bc5000
| [03fffacbe27b8000] pgd=0000000000000000, p4d=0000000000000000
| Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 6.3.0-rc3-00073-g83865133300d-dirty #4
| Hardware name: linux,dummy-virt (DT)
| pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : __kasan_unpoison_vmalloc+0xe4/0x478
| lr : __kasan_unpoison_vmalloc+0xd4/0x478
| sp : ffffcd076afd3ca0
| x29: ffffcd076afd3ca0 x28: 0068000000000f07 x27: ffff800008000000
| x26: 0000000000000000 x25: 03fffacbe27b8000 x24: ff00000000000000
| x23: ffffcd076ad3c000 x22: fffffc0000000000 x21: ffff800008000000
| x20: ffff800008004000 x19: ffff800008000000 x18: ffff800008004000
| x17: 666678302820295f x16: ffffffffffffffff x15: 0000000000000004
| x14: ffffcd076b009e88 x13: 0000000000000fff x12: 0000000000000001
| x11: 0000800008000000 x10: ffff800008000000 x9 : ffffb2f8dee00000
| x8 : 000ffffb2f8dee00 x7 : 205d303030303030 x6 : 302e30202020205b
| x5 : ffffcd076b41d63f x4 : ffffcd076afd3827 x3 : 0000000000000000
| x2 : 0000000000000000 x1 : ffffcd076afd3a30 x0 : ffffb2f8dee00000
| Call trace:
| __kasan_unpoison_vmalloc+0xe4/0x478
| __vmalloc_node_range+0x77c/0x7b8
| __vmalloc_node+0x54/0x64
| init_IRQ+0x94/0xc8
| start_kernel+0x194/0x420
| __primary_switched+0xbc/0xc4
| Code: d34cfc08 aa1f03fa 8b081b39 d503201f (f9400328)
| ---[ end trace 0000000000000000 ]---
| Kernel panic - not syncing: Attempted to kill the idle task!
This is because init_vmalloc_pages() erroneously calls virt_to_page() on
a vmalloc address, while virt_to_page() is only valid for addresses in
the linear/direct map. Since init_vmalloc_pages() expects virtual
addresses in the vmalloc range, it must use vmalloc_to_page() rather
than virt_to_page().
We call init_vmalloc_pages() from __kasan_unpoison_vmalloc(), where we
check !is_vmalloc_or_module_addr(), suggesting that we might encounter a
non-vmalloc address. Luckily, this never happens. By design, we only
call __kasan_unpoison_vmalloc() on pointers in the vmalloc area, and I
have verified that we don't violate that expectation. Given that,
is_vmalloc_or_module_addr() must always be true for any legitimate
argument to __kasan_unpoison_vmalloc().
Correct init_vmalloc_pages() to use vmalloc_to_page(), and remove the
redundant and misleading use of is_vmalloc_or_module_addr() in
__kasan_unpoison_vmalloc().
Link: https://lkml.kernel.org/r/20230418164212.1775741-1-mark.rutland@arm.com
Fixes: 6c2f761dad7851d8 ("kasan: fix zeroing vmalloc memory with HW_TAGS")
Signed-off-by: Mark Rutland <mark.rutland(a)arm.com>
Cc: Alexander Potapenko <glider(a)google.com>
Cc: Andrey Konovalov <andreyknvl(a)google.com>
Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com>
Cc: Dmitry Vyukov <dvyukov(a)google.com>
Cc: Marco Elver <elver(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/kasan/hw_tags.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/kasan/hw_tags.c~kasan-hw_tags-avoid-invalid-virt_to_page
+++ a/mm/kasan/hw_tags.c
@@ -285,7 +285,7 @@ static void init_vmalloc_pages(const voi
const void *addr;
for (addr = start; addr < start + size; addr += PAGE_SIZE) {
- struct page *page = virt_to_page(addr);
+ struct page *page = vmalloc_to_page(addr);
clear_highpage_kasan_tagged(page);
}
@@ -297,7 +297,7 @@ void *__kasan_unpoison_vmalloc(const voi
u8 tag;
unsigned long redzone_start, redzone_size;
- if (!kasan_vmalloc_enabled() || !is_vmalloc_or_module_addr(start)) {
+ if (!kasan_vmalloc_enabled()) {
if (flags & KASAN_VMALLOC_INIT)
init_vmalloc_pages(start, size);
return (void *)start;
_
Patches currently in -mm which might be from mark.rutland(a)arm.com are
kasan-hw_tags-avoid-invalid-virt_to_page.patch
Hi all,
This series is a backport of upstream commit e89c2e815e76 ("riscv:
Handle zicsr/zifencei issues between clang and binutils") to
linux-5.10.y, with the necessary machinery for CONFIG_AS_IS_GNU and
CONFIG_AS_VERSION, which that commit requires.
While the middle two patches are not strictly necessary, they are good
clean ups that ensure consistency with mainline. The first three changes
are already present in 5.15, so there is no risk of a regression moving
forward.
If there are any issues, please let me know.
NOTE: I am sending this series with 'b4 send', as that is what I am used
to at this point. Please accept my apologies if this causes any issues.
---
Masahiro Yamada (2):
kbuild: check the minimum assembler version in Kconfig
kbuild: check CONFIG_AS_IS_LLVM instead of LLVM_IAS
Nathan Chancellor (2):
kbuild: Switch to 'f' variants of integrated assembler flag
riscv: Handle zicsr/zifencei issues between clang and binutils
Makefile | 8 +++---
arch/riscv/Kconfig | 22 ++++++++++++++++
arch/riscv/Makefile | 12 +++++----
init/Kconfig | 12 +++++++++
scripts/Kconfig.include | 6 +++++
scripts/as-version.sh | 69 +++++++++++++++++++++++++++++++++++++++++++++++++
scripts/dummy-tools/gcc | 6 +++++
7 files changed, 127 insertions(+), 8 deletions(-)
---
base-commit: ca9787bdecfa2174b0a169a54916e22b89b0ef5b
change-id: 20230328-riscv-zifencei-zicsr-5-10-65596f2cac9e
Best regards,
--
Nathan Chancellor <nathan(a)kernel.org>