A number of structures and buffers passed to PKS hcalls have alignment
requirements, which could on occasion cause problems:
- Authorisation structures must be 16-byte aligned and must not cross a
page boundary
- Label structures must not cross page coundaries
- Password output buffers must not cross page boundaries
Round up the allocations of these structures/buffers to the next power of
2 to make sure this happens.
Reported-by: Benjamin Gray <bgray@xxxxxxxxxxxxx>
Fixes: 2454a7af0f2a ("powerpc/pseries: define driver for Platform KeyStore")
Signed-off-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
Reviewed-by: Russell Currey <ruscur@xxxxxxxxxx>
Signed-off-by: Russell Currey <ruscur@xxxxxxxxxx>
---
v3: Merge plpks fixes and signed update series with secvar series
---
arch/powerpc/platforms/pseries/plpks.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c
index 6d1303e4862d..91f3f623a2c7 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -112,7 +112,8 @@ static int plpks_gen_password(void)
u8 *password, consumer = PLPKS_OS_OWNER;
int rc;
- password = kzalloc(maxpwsize, GFP_KERNEL);
+ // The password must not cross a page boundary, so we align to the next power of 2
+ password = kzalloc(roundup_pow_of_two(maxpwsize), GFP_KERNEL);
if (!password)
return -ENOMEM;
@@ -148,7 +149,9 @@ static struct plpks_auth *construct_auth(u8 consumer)
if (consumer > PLPKS_OS_OWNER)
return ERR_PTR(-EINVAL);
- auth = kzalloc(struct_size(auth, password, maxpwsize), GFP_KERNEL);
+ // The auth structure must not cross a page boundary and must be
+ // 16 byte aligned. We align to the next largest power of 2
+ auth = kzalloc(roundup_pow_of_two(struct_size(auth, password, maxpwsize)), GFP_KERNEL);
if (!auth)
return ERR_PTR(-ENOMEM);
@@ -182,7 +185,8 @@ static struct label *construct_label(char *component, u8 varos, u8 *name,
if (component && slen > sizeof(label->attr.prefix))
return ERR_PTR(-EINVAL);
- label = kzalloc(sizeof(*label), GFP_KERNEL);
+ // The label structure must not cross a page boundary, so we align to the next power of 2
+ label = kzalloc(roundup_pow_of_two(sizeof(*label)), GFP_KERNEL);
if (!label)
return ERR_PTR(-ENOMEM);
--
2.39.0
