On Wed, Oct 17, 2018 at 7:19 AM Ondrej Mosnacek <omosnace@xxxxxxxxxx> 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@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 | 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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