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@xxxxxxxxxxxx>
Cc: Eli Cohen <eli@xxxxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: Doug Ledford <dledford@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 4.13+
Fixes: a806f7a1616f ("selinux: Create policydb version for Infiniband support")
Signed-off-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
---
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.
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