On Wed, Oct 17, 2018 at 7:19 AM Ondrej Mosnacek omosnace@redhat.com wrote:

Do the LE conversions before doing the Infiniband-related range checks. The incorrect checks are otherwise causing a failure to load any policy with an ibendportcon rule on BE systems. This can be reproduced by running (on e.g. ppc64):

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

Also, fix loading/storing the 64-bit subnet prefix for OCON_IBPKEY to use a correctly aligned buffer.

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 | 41 ++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 14 deletions(-)

Changes in v3:

• use separate buffer for the 64-bit subnet_prefix
• add comments on the byte ordering of subnet_prefix
• deduplicate the le32_to_cpu() calls from checks

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..b9029491869b 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -2108,6 +2108,7 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, { int i, j, rc; u32 nel, len;

•   __be64 prefixbuf[1];
    __le32 buf[3];
    struct ocontext *l, *c;
    u32 nodebuf[8];
  

@@ -2218,21 +2219,26 @@ 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(prefixbuf, fp, sizeof(u64));
                            if (rc)
                                    goto out;
  
  

•                           c->u.ibpkey.subnet_prefix = be64_to_cpu(*((__be64 *)nodebuf));
  

•                           /* we need to have subnet_prefix in CPU order */
  

•                           c->u.ibpkey.subnet_prefix = be64_to_cpu(prefixbuf[0]);
  
  

•                           if (nodebuf[2] > 0xffff ||
  

•                               nodebuf[3] > 0xffff) {
  

•                           rc = next_entry(buf, fp, sizeof(u32) * 2);
  

•                           if (rc)
  

•                                   goto out;
  

•                           c->u.ibpkey.low_pkey  = le32_to_cpu(buf[0]);
  

•                           c->u.ibpkey.high_pkey = le32_to_cpu(buf[1]);
  

We noticed this in the coresponding user space patch. Assigning 32 to 16 truncates the values and thus the conditionals below are always false.

struct { u64 subnet_prefix; u16 low_pkey; <-- u16 u16 high_pkey; <-- u16 } ibpkey;

I figured I would comment just to make sure folks following one patch and not the other are informed. You'll need to respin a v4 and asign to a u32 intermediate, range check and the assign.

•                           if (c->u.ibpkey.low_pkey  > 0xffff ||
  

•                               c->u.ibpkey.high_pkey > 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]);
  

•                           rc = context_read_and_validate(&c->context[0],
                                                           p,
                                                           fp);
  

@@ -2249,13 +2255,14 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, if (rc) goto out;

•                           if (buf[1] > 0xff || buf[1] == 0) {
  

•                           c->u.ibendport.port = le32_to_cpu(buf[1]);
  

•                           if (c->u.ibendport.port > 0xff ||
  

•                               c->u.ibendport.port == 0) {
                                    rc = -EINVAL;
                                    goto out;
                            }
  
  

•                           c->u.ibendport.port = le32_to_cpu(buf[1]);
  

•                           rc = context_read_and_validate(&c->context[0],
                                                           p,
                                                           fp);
  

@@ -3105,6 +3112,7 @@ static int ocontext_write(struct policydb *p, struct policydb_compat_info *info, { unsigned int i, j, rc; size_t nel, len;

•   __be64 prefixbuf[1];
    __le32 buf[3];
    u32 nodebuf[8];
    struct ocontext *c;
  

@@ -3192,12 +3200,17 @@ 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);
  

•                           /* subnet_prefix is in CPU order */
  

•                           prefixbuf[0] = cpu_to_be64(c->u.ibpkey.subnet_prefix);
  
  

•                           nodebuf[2] = cpu_to_le32(c->u.ibpkey.low_pkey);
  

•                           nodebuf[3] = cpu_to_le32(c->u.ibpkey.high_pkey);
  

•                           rc = put_entry(prefixbuf, sizeof(u64), 1, fp);
  

•                           if (rc)
  

•                                   return rc;
  

•                           buf[0] = cpu_to_le32(c->u.ibpkey.low_pkey);
  

•                           buf[1] = cpu_to_le32(c->u.ibpkey.high_pkey);
  
  

•                           rc = put_entry(nodebuf, sizeof(u32), 4, fp);
  

•                           rc = put_entry(buf, sizeof(u32), 2, fp);
                            if (rc)
                                    return rc;
                            rc = context_write(p, &c->context[0], fp);
  

-- 2.17.2

---

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