The source for the Linux kernel used in Windows Subsystem for Linux 2 (WSL2)
Перейти к файлу
Patrick Wang 23c2d497de mm: kmemleak: take a full lowmem check in kmemleak_*_phys()
The kmemleak_*_phys() apis do not check the address for lowmem's min
boundary, while the caller may pass an address below lowmem, which will
trigger an oops:

  # echo scan > /sys/kernel/debug/kmemleak
  Unable to handle kernel paging request at virtual address ff5fffffffe00000
  Oops [#1]
  Modules linked in:
  CPU: 2 PID: 134 Comm: bash Not tainted 5.18.0-rc1-next-20220407 #33
  Hardware name: riscv-virtio,qemu (DT)
  epc : scan_block+0x74/0x15c
   ra : scan_block+0x72/0x15c
  epc : ffffffff801e5806 ra : ffffffff801e5804 sp : ff200000104abc30
   gp : ffffffff815cd4e8 tp : ff60000004cfa340 t0 : 0000000000000200
   t1 : 00aaaaaac23954cc t2 : 00000000000003ff s0 : ff200000104abc90
   s1 : ffffffff81b0ff28 a0 : 0000000000000000 a1 : ff5fffffffe01000
   a2 : ffffffff81b0ff28 a3 : 0000000000000002 a4 : 0000000000000001
   a5 : 0000000000000000 a6 : ff200000104abd7c a7 : 0000000000000005
   s2 : ff5fffffffe00ff9 s3 : ffffffff815cd998 s4 : ffffffff815d0e90
   s5 : ffffffff81b0ff28 s6 : 0000000000000020 s7 : ffffffff815d0eb0
   s8 : ffffffffffffffff s9 : ff5fffffffe00000 s10: ff5fffffffe01000
   s11: 0000000000000022 t3 : 00ffffffaa17db4c t4 : 000000000000000f
   t5 : 0000000000000001 t6 : 0000000000000000
  status: 0000000000000100 badaddr: ff5fffffffe00000 cause: 000000000000000d
    scan_gray_list+0x12e/0x1a6
    kmemleak_scan+0x2aa/0x57e
    kmemleak_write+0x32a/0x40c
    full_proxy_write+0x56/0x82
    vfs_write+0xa6/0x2a6
    ksys_write+0x6c/0xe2
    sys_write+0x22/0x2a
    ret_from_syscall+0x0/0x2

The callers may not quite know the actual address they pass(e.g. from
devicetree).  So the kmemleak_*_phys() apis should guarantee the address
they finally use is in lowmem range, so check the address for lowmem's
min boundary.

Link: https://lkml.kernel.org/r/20220413122925.33856-1-patrick.wang.shcn@gmail.com
Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-15 14:49:56 -07:00
Documentation
LICENSES
arch
block
certs
crypto
drivers
fs
include
init
ipc
kernel
lib
mm
net
samples
scripts
security
sound
tools
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile
README

README

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.