4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ram Pai linuxram@us.ibm.com
commit de113256f8c1c24d8c79ae388bf2a5abd70f7577 upstream.
Deny all permissions on all keys, with some exceptions. pkey-0 must allow all permissions, or else everything comes to a screaching halt. Execute-only key must allow execute permission.
Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Ram Pai linuxram@us.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/mm/pkeys.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
--- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -124,12 +124,10 @@ int pkey_initialize(void)
/* register mask is in BE format */ pkey_amr_mask = ~0x0ul; - pkey_iamr_mask = ~0x0ul; + pkey_amr_mask &= ~(0x3ul << pkeyshift(0));
- for (i = 0; i < (pkeys_total - os_reserved); i++) { - pkey_amr_mask &= ~(0x3ul << pkeyshift(i)); - pkey_iamr_mask &= ~(0x1ul << pkeyshift(i)); - } + pkey_iamr_mask = ~0x0ul; + pkey_iamr_mask &= ~(0x3ul << pkeyshift(0));
pkey_uamor_mask = ~0x0ul; pkey_uamor_mask &= ~(0x3ul << pkeyshift(0));