On 10/16/2018 03:09 AM, Ondrej Mosnacek wrote:
Add missing LE conversions to the Infiniband-related range checks. These were causing a failure to load any policy with an ibendportcon rule on BE systems. This can be reproduced by running:
cat >my_module.cil <<EOF (type test_ibendport_t) (roletype object_r test_ibendport_t) (ibendportcon mlx4_0 1 (system_u object_r test_ibendport_t ((s0) (s0)))) EOF semodule -i my_module.cil
(On ppc64 it fails with "/sbin/load_policy: Can't load policy: Invalid argument")
Also, the temporary buffers are only guaranteed to be aligned for 32-bit access so use (get/put)_unaligned_be64() for 64-bit accesses.
Finally, do not use the 'nodebuf' (u32) buffer where 'buf' (__le32) should be used instead.
Tested internally on a ppc64 machine with a RHEL 7 kernel with this patch applied.
Cc: Daniel Jurgens danielj@mellanox.com Cc: Eli Cohen eli@mellanox.com Cc: James Morris jmorris@namei.org Cc: Doug Ledford dledford@redhat.com Cc: stable@vger.kernel.org # 4.13+ Fixes: a806f7a1616f ("selinux: Create policydb version for Infiniband support") Signed-off-by: Ondrej Mosnacek omosnace@redhat.com
security/selinux/ss/policydb.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-)
Changes in v2:
- add reproducer to commit message
- update e-mail address of James Morris
- better Cc also the old SELinux ML
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index f4eadd3f7350..2b310e8f2923 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -37,6 +37,7 @@ #include <linux/errno.h> #include <linux/audit.h> #include <linux/flex_array.h> +#include <asm/unaligned.h> #include "security.h" #include "policydb.h" @@ -2108,7 +2109,7 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, { int i, j, rc; u32 nel, len;
- __le32 buf[3];
- __le32 buf[4]; struct ocontext *l, *c; u32 nodebuf[8];
@@ -2218,20 +2219,20 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, break; } case OCON_IBPKEY:
rc = next_entry(nodebuf, fp, sizeof(u32) * 4);
rc = next_entry(buf, fp, sizeof(u32) * 4); if (rc) goto out;
c->u.ibpkey.subnet_prefix = be64_to_cpu(*((__be64 *)nodebuf));
c->u.ibpkey.subnet_prefix = get_unaligned_be64(buf);
if (nodebuf[2] > 0xffff ||nodebuf[3] > 0xffff) {
if (le32_to_cpu(buf[2]) > 0xffff ||le32_to_cpu(buf[3]) > 0xffff) { rc = -EINVAL; goto out; }
c->u.ibpkey.low_pkey = le32_to_cpu(nodebuf[2]);c->u.ibpkey.high_pkey = le32_to_cpu(nodebuf[3]);
c->u.ibpkey.low_pkey = le32_to_cpu(buf[2]);c->u.ibpkey.high_pkey = le32_to_cpu(buf[3]);
I'm wondering why the handling here is inconsistent with that of OCON_NODE/OCON_NODE6, which also deals with network byte order / big endian data. Also it is inconsistent with the corresponding userspace code in libsepol for IBPKEY, which just does a memcpy() for copying between the subnet_prefix and the buffer.
Switching to buf entirely doesn't seem right since it is __le32 and the first part is actually __be64.
Maybe we ought to be splitting this into two next_entry() calls, one to fetch the be64 subnet prefix into an appropriately aligned and typed buffer and one to fetch the le32 low/high pkey values into buf?
We also need to fix the libsepol code (selinux/libsepol/src/policydb.c:ocontext_read_selinux) for the validity check at least.
rc = context_read_and_validate(&c->context[0], p, @@ -2249,7 +2250,8 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, if (rc) goto out;
if (buf[1] > 0xff || buf[1] == 0) {
if (le32_to_cpu(buf[1]) > 0xff ||le32_to_cpu(buf[1]) == 0) { rc = -EINVAL; goto out; }@@ -3105,7 +3107,7 @@ static int ocontext_write(struct policydb *p, struct policydb_compat_info *info, { unsigned int i, j, rc; size_t nel, len;
- __le32 buf[3];
- __le32 buf[4]; u32 nodebuf[8]; struct ocontext *c; for (i = 0; i < info->ocon_num; i++) {
@@ -3192,12 +3194,12 @@ static int ocontext_write(struct policydb *p, struct policydb_compat_info *info, return rc; break; case OCON_IBPKEY:
*((__be64 *)nodebuf) = cpu_to_be64(c->u.ibpkey.subnet_prefix);
put_unaligned_be64(c->u.ibpkey.subnet_prefix, buf);
nodebuf[2] = cpu_to_le32(c->u.ibpkey.low_pkey);nodebuf[3] = cpu_to_le32(c->u.ibpkey.high_pkey);
buf[2] = cpu_to_le32(c->u.ibpkey.low_pkey);buf[3] = cpu_to_le32(c->u.ibpkey.high_pkey);
rc = put_entry(nodebuf, sizeof(u32), 4, fp);
rc = put_entry(buf, sizeof(u32), 4, fp); if (rc) return rc; rc = context_write(p, &c->context[0], fp);
Likewise this doesn't seem consistent with the OCONTEXT_NODE/NODE6 handling here or the libsepol ocontext_write_selinux code for OCON_IBPKEY. We could also split this into two put_entry() calls to preserve the typing separation between the be64 and le32 data.