4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ram Pai <linuxram@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx # v4.16+
Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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));
