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 784a4661. ] Fixes: 33a709b2 ("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
parent
2f5b3514