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Mark Rutland 29083fd84d kasan: hw_tags: avoid invalid virt_to_page()
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: 6c2f761dad ("kasan: fix zeroing vmalloc memory with HW_TAGS")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-02 17:23:27 -07:00
arch Add support for new Linear Address Masking CPU feature. This is similar 2023-04-28 09:43:49 -07:00
block Driver core changes for 6.4-rc1 2023-04-27 11:53:57 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto modules-6.4-rc1 2023-04-27 16:36:55 -07:00
Documentation * Improve AMX documentation along with example code 2023-04-28 09:32:34 -07:00
drivers Add support for new Linear Address Masking CPU feature. This is similar 2023-04-28 09:43:49 -07:00
fs Add support for new Linear Address Masking CPU feature. This is similar 2023-04-28 09:43:49 -07:00
include Add support for new Linear Address Masking CPU feature. This is similar 2023-04-28 09:43:49 -07:00
init - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
io_uring Networking changes for 6.4. 2023-04-26 16:07:23 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
lib Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm kasan: hw_tags: avoid invalid virt_to_page() 2023-05-02 17:23:27 -07:00
net - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
rust rust: allow to use INIT_STACK_ALL_ZERO 2023-04-19 19:34:43 +02:00
samples - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
scripts Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
security - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
sound Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
tools Add support for new Linear Address Masking CPU feature. This is similar 2023-04-28 09:43:49 -07:00
usr initramfs: Check negative timestamp to prevent broken cpio archive 2023-04-16 17:37:01 +09:00
virt KVM: PPC: Make KVM_CAP_IRQFD_RESAMPLE platform dependent 2023-03-31 11:19:05 -04:00
.clang-format PCI: Introduce pci_dev_for_each_resource() 2023-04-04 10:43:52 -05:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for *.dtso files 2023-02-26 15:28:23 +09:00
.gitignore linux-kselftest-kunit-6.4-rc1 2023-04-24 12:31:32 -07:00
.mailmap Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Char/Misc drivers for 6.4-rc1 2023-04-27 12:07:50 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
Makefile Linux 6.3 2023-04-23 12:02:52 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.