linux/arch/x86/platform
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
..
atom Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
ce4100 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
efi efi/x86: avoid KASAN false positives when accessing the 1: 1 mapping 2020-01-20 08:14:29 +01:00
geode Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 17:49:45 -07:00
goldfish treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
intel x86/platform/intel/iosf_mbi Rewrite locking 2019-08-19 20:52:39 +02:00
intel-mid treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
intel-quark x86: platform: no need to check return value of debugfs_create functions 2019-06-03 16:18:12 +02:00
iris treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 70 2019-05-24 17:36:47 +02:00
olpc - Core Frameworks 2019-12-01 16:16:31 -08:00
pvh x86/asm: Make some functions local 2019-10-18 11:34:39 +02:00
scx200 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
sfi x86: Use pr_warn instead of pr_warning 2019-10-18 15:00:18 +02:00
ts5500 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
uv efi/x86: Limit EFI old memory map to SGI UV machines 2020-01-20 08:13:01 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00