diff options
| author | Andrew Cooper | 2021-12-16 00:08:56 +0000 |
|---|---|---|
| committer | Borislav Petkov | 2021-12-19 22:44:34 +0100 |
| commit | 57690554abe135fee81d6ac33cc94d75a7e224bb (patch) | |
| tree | 1d37e7da63f3fda967a274742cb1e55e2cd3243b /arch | |
| parent | 2f5b3514c33fecad4003ce0f22ca9691492d310b (diff) | |
x86/pkey: Fix undefined behaviour with PKRU_WD_BIT
Both __pkru_allows_write() and arch_set_user_pkey_access() shift
PKRU_WD_BIT (a signed constant) by up to 30 bits, hitting the
sign bit.
Use unsigned constants instead.
Clearly pkey 15 has not been used in combination with UBSAN yet.
Noticed by code inspection only. I can't actually provoke the
compiler into generating incorrect logic as far as this shift is
concerned.
[
dhansen: add stable@ tag, plus minor changelog massaging,
For anyone doing backports, these #defines were in
arch/x86/include/asm/pgtable.h before 784a46618f6.
]
Fixes: 33a709b25a76 ("mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20211216000856.4480-1-andrew.cooper3@citrix.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/pkru.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/include/asm/pkru.h b/arch/x86/include/asm/pkru.h index 4cd49afa0ca4..74f0a2d34ffd 100644 --- a/arch/x86/include/asm/pkru.h +++ b/arch/x86/include/asm/pkru.h @@ -4,8 +4,8 @@ #include <asm/cpufeature.h> -#define PKRU_AD_BIT 0x1 -#define PKRU_WD_BIT 0x2 +#define PKRU_AD_BIT 0x1u +#define PKRU_WD_BIT 0x2u #define PKRU_BITS_PER_PKEY 2 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS |