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| author | Ard Biesheuvel <ardb@kernel.org> | 2020-01-18 17:57:03 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-01-20 08:14:29 +0100 |
| commit | 3cc028619e284188cdde652631e1c3c5a83692b9 (patch) | |
| tree | bad91cc8c7b4a8fcd754dcfccccf83e54cd66dc9 /arch/x86/platform | |
| parent | 484a418d075488c6999528247cc711d12c373447 (diff) | |
| download | linux-3cc028619e284188cdde652631e1c3c5a83692b9.tar.bz2 | |
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: 698294704573 ("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>
Diffstat (limited to 'arch/x86/platform')
| -rw-r--r-- | arch/x86/platform/efi/efi_64.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 8d1869ff1033..e2accfe636bd 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -543,7 +543,7 @@ static DEFINE_SPINLOCK(efi_runtime_lock); __s; \ }) -static efi_status_t __init +static efi_status_t __init __no_sanitize_address efi_thunk_set_virtual_address_map(unsigned long memory_map_size, unsigned long descriptor_size, u32 descriptor_version, @@ -882,10 +882,11 @@ void __init efi_thunk_runtime_setup(void) efi.query_capsule_caps = efi_thunk_query_capsule_caps; } -efi_status_t __init efi_set_virtual_address_map(unsigned long memory_map_size, - unsigned long descriptor_size, - u32 descriptor_version, - efi_memory_desc_t *virtual_map) +efi_status_t __init __no_sanitize_address +efi_set_virtual_address_map(unsigned long memory_map_size, + unsigned long descriptor_size, + u32 descriptor_version, + efi_memory_desc_t *virtual_map) { efi_status_t status; unsigned long flags; |