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Ard Biesheuvel 3cc028619e efi/x86: avoid KASAN false positives when accessing the 1: 1 mapping
When installing the EFI virtual address map during early boot, we
access the EFI system table to retrieve the 1:1 mapped address of
the SetVirtualAddressMap() EFI runtime service. This memory is not
known to KASAN, so on KASAN enabled builds, this may result in a
splat like

  ==================================================================
  BUG: KASAN: user-memory-access in efi_set_virtual_address_map+0x141/0x354
  Read of size 4 at addr 000000003fbeef38 by task swapper/0/0

  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc5+ #758
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Call Trace:
   dump_stack+0x8b/0xbb
   ? efi_set_virtual_address_map+0x141/0x354
   ? efi_set_virtual_address_map+0x141/0x354
   __kasan_report+0x176/0x192
   ? efi_set_virtual_address_map+0x141/0x354
   kasan_report+0xe/0x20
   efi_set_virtual_address_map+0x141/0x354
   ? efi_thunk_runtime_setup+0x148/0x148
   ? __inc_numa_state+0x19/0x90
   ? memcpy+0x34/0x50
   efi_enter_virtual_mode+0x5fd/0x67d
   start_kernel+0x5cd/0x682
   ? mem_encrypt_init+0x6/0x6
   ? x86_family+0x5/0x20
   ? load_ucode_bsp+0x46/0x154
   secondary_startup_64+0xa4/0xb0
  ==================================================================

Since this code runs only a single time during early boot, let's annotate
it as __no_sanitize_address so KASAN disregards it entirely.

Fixes: 6982947045 ("efi/x86: Split SetVirtualAddresMap() wrappers into ...")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-20 08:14:29 +01:00
arch efi/x86: avoid KASAN false positives when accessing the 1: 1 mapping 2020-01-20 08:14:29 +01:00
block block: fix an integer overflow in logical block size 2020-01-15 21:43:09 -07:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto tpmdd fixes for Linux v5.5-rc3 2019-12-18 17:17:36 -08:00
Documentation efi/x86: Limit EFI old memory map to SGI UV machines 2020-01-20 08:13:01 +01:00
drivers efi: Fix handling of multiple efi_fake_mem= entries 2020-01-20 08:14:29 +01:00
fs io_uring-5.5-2020-01-16 2020-01-17 11:25:45 -08:00
include efi: Fix handling of multiple efi_fake_mem= entries 2020-01-20 08:14:29 +01:00
init mm, debug_pagealloc: don't rely on static keys too early 2020-01-13 18:19:02 -08:00
ipc treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-19 12:03:53 -08:00
lib lib/vdso: Make __cvdso_clock_getres() static 2020-01-10 19:29:01 +01:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Linux 5.5-rc7 2020-01-20 08:05:16 +01:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-19 12:03:53 -08:00
samples samples/seccomp: Zero out members based on seccomp_notif_sizes 2020-01-02 13:03:39 -08:00
scripts Kbuild fixes for v5.5 (2nd) 2020-01-03 11:21:25 -08:00
security + Bug fixes 2020-01-04 19:28:30 -08:00
sound sound fixes for 5.5-rc7 2020-01-17 08:38:35 -08:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-19 12:03:53 -08:00
usr gen_initramfs_list.sh: fix 'bad variable name' error 2020-01-04 00:00:48 +09:00
virt PPC KVM fix for 5.5 2019-12-22 13:18:15 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap MAINTAINERS: update my email address 2020-01-11 14:33:39 -08:00
COPYING
CREDITS Linux 5.4-rc4 2019-10-29 04:43:29 -06:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-19 12:03:53 -08:00
Makefile Linux 5.5-rc7 2020-01-19 16:02:49 -08:00
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.