Messages in this thread Patch in this message | | | From | Andrew Donnellan <> | Subject | [PATCH v4 02/24] powerpc/pseries: Fix alignment of PLPKS structures and buffers | Date | Fri, 20 Jan 2023 18:42:44 +1100 |
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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 boundaries
- 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@linux.ibm.com> Fixes: 2454a7af0f2a ("powerpc/pseries: define driver for Platform KeyStore") Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Russell Currey <ruscur@russell.cc>
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v3: Merge plpks fixes and signed update series with secvar series
v4: Fix typo in commit message
Move up in series (npiggin) --- 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 9e85b6d85b0b..a01cf2ff140a 100644 --- a/arch/powerpc/platforms/pseries/plpks.c +++ b/arch/powerpc/platforms/pseries/plpks.c @@ -126,7 +126,8 @@ static int plpks_gen_password(void) u8 *password, consumer = PKS_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; @@ -162,7 +163,9 @@ static struct plpks_auth *construct_auth(u8 consumer) if (consumer > PKS_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); @@ -196,7 +199,8 @@ 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
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