[PATCH v5] selinux: policydb - fix byte order and alignment issues
DORMANTno replies
From: Ondrej Mosnacek <hidden>
Date: 2018-10-22 16:30:13
Also in:
selinux
Subsystem:
selinux security module, the rest · Maintainers:
Paul Moore, Stephen Smalley, Linus Torvalds
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 <redacted>
Cc: Eli Cohen <redacted>
Cc: James Morris <jmorris@namei.org>
Cc: Doug Ledford <redacted>
Cc: <redacted> # 4.13+
Fixes: a806f7a1616f ("selinux: Create policydb version for Infiniband support")
Signed-off-by: Ondrej Mosnacek <redacted>
---
security/selinux/ss/policydb.c | 51 ++++++++++++++++++++++++----------
1 file changed, 36 insertions(+), 15 deletions(-)
Changes in v5:
- defer also assignment to 8-bit ibendport.port
Changes in v4:
- defer assignment to 16-bit struct fields to after the range check
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..d7e8126f32dc 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];
@@ -2217,21 +2218,30 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, goto out; break; } - case OCON_IBPKEY: - rc = next_entry(nodebuf, fp, sizeof(u32) * 4); + case OCON_IBPKEY: { + u32 pkey_lo, pkey_hi; + + rc = next_entry(prefixbuf, fp, sizeof(u64)); + if (rc) + goto out; + + /* we need to have subnet_prefix in CPU order */ + c->u.ibpkey.subnet_prefix = be64_to_cpu(prefixbuf[0]); + + rc = next_entry(buf, fp, sizeof(u32) * 2); if (rc) goto out; - c->u.ibpkey.subnet_prefix = be64_to_cpu(*((__be64 *)nodebuf)); + pkey_lo = le32_to_cpu(buf[0]); + pkey_hi = le32_to_cpu(buf[1]); - if (nodebuf[2] > 0xffff || - nodebuf[3] > 0xffff) { + if (pkey_lo > U16_MAX || pkey_hi > U16_MAX) { 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 = pkey_lo; + c->u.ibpkey.high_pkey = pkey_hi; rc = context_read_and_validate(&c->context[0], p,
@@ -2239,7 +2249,10 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, if (rc) goto out; break; - case OCON_IBENDPORT: + } + case OCON_IBENDPORT: { + u32 port; + rc = next_entry(buf, fp, sizeof(u32) * 2); if (rc) goto out;
@@ -2249,12 +2262,13 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, if (rc) goto out; - if (buf[1] > 0xff || buf[1] == 0) { + port = le32_to_cpu(buf[1]); + if (port > 0xff || port == 0) { rc = -EINVAL; goto out; } - c->u.ibendport.port = le32_to_cpu(buf[1]); + c->u.ibendport.port = port; rc = context_read_and_validate(&c->context[0], p,
@@ -2262,7 +2276,8 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, if (rc) goto out; break; - } + } /* end case */ + } /* end switch */ } } rc = 0;
@@ -3105,6 +3120,7 @@ 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 +3208,17 @@ 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