diff options
Diffstat (limited to 'security/selinux/xfrm.c')
-rw-r--r-- | security/selinux/xfrm.c | 199 |
1 files changed, 90 insertions, 109 deletions
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c index d03081886214..07ae0c06dfc3 100644 --- a/security/selinux/xfrm.c +++ b/security/selinux/xfrm.c @@ -74,6 +74,54 @@ static inline int selinux_authorizable_xfrm(struct xfrm_state *x) } /* + * Allocates a xfrm_sec_state and populates it using the supplied security + * xfrm_user_sec_ctx context. + */ +static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp, + struct xfrm_user_sec_ctx *uctx) +{ + int rc; + const struct task_security_struct *tsec = current_security(); + struct xfrm_sec_ctx *ctx = NULL; + u32 str_len; + + if (ctxp == NULL || uctx == NULL || + uctx->ctx_doi != XFRM_SC_DOI_LSM || + uctx->ctx_alg != XFRM_SC_ALG_SELINUX) + return -EINVAL; + + str_len = uctx->ctx_len; + if (str_len >= PAGE_SIZE) + return -ENOMEM; + + ctx = kmalloc(sizeof(*ctx) + str_len + 1, GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->ctx_doi = XFRM_SC_DOI_LSM; + ctx->ctx_alg = XFRM_SC_ALG_SELINUX; + ctx->ctx_len = str_len; + memcpy(ctx->ctx_str, &uctx[1], str_len); + ctx->ctx_str[str_len] = '\0'; + rc = security_context_to_sid(ctx->ctx_str, str_len, &ctx->ctx_sid); + if (rc) + goto err; + + rc = avc_has_perm(tsec->sid, ctx->ctx_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, NULL); + if (rc) + goto err; + + *ctxp = ctx; + atomic_inc(&selinux_xfrm_refcount); + return 0; + +err: + kfree(ctx); + return rc; +} + +/* * LSM hook implementation that authorizes that a flow can use * a xfrm policy rule. */ @@ -191,111 +239,13 @@ int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall) } /* - * Security blob allocation for xfrm_policy and xfrm_state - * CTX does not have a meaningful value on input - */ -static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp, - struct xfrm_user_sec_ctx *uctx, u32 sid) -{ - int rc = 0; - const struct task_security_struct *tsec = current_security(); - struct xfrm_sec_ctx *ctx = NULL; - char *ctx_str = NULL; - u32 str_len; - - BUG_ON(uctx && sid); - - if (!uctx) - goto not_from_user; - - if (uctx->ctx_alg != XFRM_SC_ALG_SELINUX) - return -EINVAL; - - str_len = uctx->ctx_len; - if (str_len >= PAGE_SIZE) - return -ENOMEM; - - *ctxp = ctx = kmalloc(sizeof(*ctx) + - str_len + 1, - GFP_KERNEL); - - if (!ctx) - return -ENOMEM; - - ctx->ctx_doi = uctx->ctx_doi; - ctx->ctx_len = str_len; - ctx->ctx_alg = uctx->ctx_alg; - - memcpy(ctx->ctx_str, - uctx+1, - str_len); - ctx->ctx_str[str_len] = 0; - rc = security_context_to_sid(ctx->ctx_str, - str_len, - &ctx->ctx_sid); - - if (rc) - goto out; - - /* - * Does the subject have permission to set security context? - */ - rc = avc_has_perm(tsec->sid, ctx->ctx_sid, - SECCLASS_ASSOCIATION, - ASSOCIATION__SETCONTEXT, NULL); - if (rc) - goto out; - - return rc; - -not_from_user: - rc = security_sid_to_context(sid, &ctx_str, &str_len); - if (rc) - goto out; - - *ctxp = ctx = kmalloc(sizeof(*ctx) + - str_len, - GFP_ATOMIC); - - if (!ctx) { - rc = -ENOMEM; - goto out; - } - - ctx->ctx_doi = XFRM_SC_DOI_LSM; - ctx->ctx_alg = XFRM_SC_ALG_SELINUX; - ctx->ctx_sid = sid; - ctx->ctx_len = str_len; - memcpy(ctx->ctx_str, - ctx_str, - str_len); - - goto out2; - -out: - *ctxp = NULL; - kfree(ctx); -out2: - kfree(ctx_str); - return rc; -} - -/* * LSM hook implementation that allocs and transfers uctx spec to * xfrm_policy. */ int selinux_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, struct xfrm_user_sec_ctx *uctx) { - int err; - - BUG_ON(!uctx); - - err = selinux_xfrm_sec_ctx_alloc(ctxp, uctx, 0); - if (err == 0) - atomic_inc(&selinux_xfrm_refcount); - - return err; + return selinux_xfrm_alloc_user(ctxp, uctx); } @@ -347,20 +297,51 @@ int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx) } /* - * LSM hook implementation that allocs and transfers sec_ctx spec to - * xfrm_state. + * LSM hook implementation that allocates a xfrm_sec_state, populates it using + * the supplied security context, and assigns it to the xfrm_state. + */ +int selinux_xfrm_state_alloc(struct xfrm_state *x, + struct xfrm_user_sec_ctx *uctx) +{ + return selinux_xfrm_alloc_user(&x->security, uctx); +} + +/* + * LSM hook implementation that allocates a xfrm_sec_state and populates based + * on a secid. */ -int selinux_xfrm_state_alloc(struct xfrm_state *x, struct xfrm_user_sec_ctx *uctx, - u32 secid) +int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x, + struct xfrm_sec_ctx *polsec, u32 secid) { - int err; + int rc; + struct xfrm_sec_ctx *ctx; + char *ctx_str = NULL; + int str_len; - BUG_ON(!x); + if (!polsec) + return 0; - err = selinux_xfrm_sec_ctx_alloc(&x->security, uctx, secid); - if (err == 0) - atomic_inc(&selinux_xfrm_refcount); - return err; + if (secid == 0) + return -EINVAL; + + rc = security_sid_to_context(secid, &ctx_str, &str_len); + if (rc) + return rc; + + ctx = kmalloc(sizeof(*ctx) + str_len, GFP_ATOMIC); + if (!ctx) + return -ENOMEM; + + ctx->ctx_doi = XFRM_SC_DOI_LSM; + ctx->ctx_alg = XFRM_SC_ALG_SELINUX; + ctx->ctx_sid = secid; + ctx->ctx_len = str_len; + memcpy(ctx->ctx_str, ctx_str, str_len); + kfree(ctx_str); + + x->security = ctx; + atomic_inc(&selinux_xfrm_refcount); + return 0; } /* |