From: Borislav Petkov <bp@alien8.de>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: x86@kernel.org, linux-sgx@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
Jethro Beekman <jethro@fortanix.com>,
Haitao Huang <haitao.huang@linux.intel.com>,
Chunyang Hui <sanqian.hcy@antfin.com>,
Jordan Hand <jorhand@linux.microsoft.com>,
Nathaniel McCallum <npmccallum@redhat.com>,
Seth Moore <sethmo@google.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Suresh Siddha <suresh.b.siddha@intel.com>,
akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com,
asapek@google.com, cedric.xing@intel.com,
chenalexchen@google.com, conradparker@google.com,
cyhanish@google.com, dave.hansen@intel.com,
haitao.huang@intel.com, josh@joshtriplett.org,
kai.huang@intel.com, kai.svahn@intel.com, kmoy@google.com,
ludloff@google.com, luto@kernel.org, nhorman@redhat.com,
puiterwijk@redhat.com, rientjes@google.com, tglx@linutronix.de,
yaozhangx@google.com
Subject: Re: [PATCH v33 11/21] x86/sgx: Linux Enclave Driver
Date: Fri, 26 Jun 2020 11:14:19 +0200 [thread overview]
Message-ID: <20200626091419.GB27151@zn.tnic> (raw)
In-Reply-To: <20200617220844.57423-12-jarkko.sakkinen@linux.intel.com>
On Thu, Jun 18, 2020 at 01:08:33AM +0300, Jarkko Sakkinen wrote:
> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> index 59472cd6a11d..35f713e3a267 100644
> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> @@ -323,6 +323,7 @@ Code Seq# Include File Comments
> <mailto:tlewis@mindspring.com>
> 0xA3 90-9F linux/dtlk.h
> 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem
> +0xA4 00-1F uapi/asm/sgx.h Intel SGX subsystem (a legit conflict as TEE and SGX do not co-exist)
Maybe add <mailto:linux-sgx@vger.kernel.org> ?
> 0xAA 00-3F linux/uapi/linux/userfaultfd.h
> 0xAB 00-1F linux/nbd.h
> 0xAC 00-1F linux/raw.h
...
> +static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
> +{
> + unsigned long encl_size = secs->size + PAGE_SIZE;
Wait, you just copied @secs from user memory in sgx_ioc_enclave_create()
and now use ->size unverified? You're kidding, right?
> + struct sgx_epc_page *secs_epc;
> + unsigned long ssaframesize;
> + struct sgx_pageinfo pginfo;
> + struct sgx_secinfo secinfo;
> + struct file *backing;
> + long ret;
> +
> + if (atomic_read(&encl->flags) & SGX_ENCL_CREATED)
> + return -EINVAL;
> +
> + ssaframesize = sgx_calc_ssaframesize(secs->miscselect, secs->xfrm);
So this is using more un-validated user input to do further calculations.
What can possibly go wrong?
I sure hope *I* am wrong and am missing something here.
If not, please, for the next version, audit all your user input and
validate it before using it. Srsly.
> + if (sgx_validate_secs(secs, ssaframesize)) {
> + pr_debug("invalid SECS\n");
> + return -EINVAL;
> + }
> +
> + backing = shmem_file_setup("SGX backing", encl_size + (encl_size >> 5),
> + VM_NORESERVE);
> + if (IS_ERR(backing))
> + return PTR_ERR(backing);
> +
> + encl->backing = backing;
> +
> + secs_epc = __sgx_alloc_epc_page();
> + if (IS_ERR(secs_epc)) {
> + ret = PTR_ERR(secs_epc);
> + goto err_out_backing;
> + }
> +
> + encl->secs.epc_page = secs_epc;
> +
> + pginfo.addr = 0;
> + pginfo.contents = (unsigned long)secs;
> + pginfo.metadata = (unsigned long)&secinfo;
> + pginfo.secs = 0;
> + memset(&secinfo, 0, sizeof(secinfo));
> +
> + ret = __ecreate((void *)&pginfo, sgx_get_epc_addr(secs_epc));
> + if (ret) {
> + pr_debug("ECREATE returned %ld\n", ret);
> + goto err_out;
> + }
> +
> + if (secs->attributes & SGX_ATTR_DEBUG)
> + atomic_or(SGX_ENCL_DEBUG, &encl->flags);
> +
> + encl->secs.encl = encl;
> + encl->secs_attributes = secs->attributes;
> + encl->allowed_attributes |= SGX_ATTR_ALLOWED_MASK;
> + encl->base = secs->base;
> + encl->size = secs->size;
> + encl->ssaframesize = secs->ssa_frame_size;
> +
> + /*
> + * Set SGX_ENCL_CREATED only after the enclave is fully prepped. This
> + * allows setting and checking enclave creation without having to take
> + * encl->lock.
> + */
> + atomic_or(SGX_ENCL_CREATED, &encl->flags);
> +
> + return 0;
> +
> +err_out:
> + sgx_free_epc_page(encl->secs.epc_page);
> + encl->secs.epc_page = NULL;
> +
> +err_out_backing:
> + fput(encl->backing);
> + encl->backing = NULL;
> +
> + return ret;
> +}
> +
> +/**
> + * sgx_ioc_enclave_create - handler for %SGX_IOC_ENCLAVE_CREATE
> + * @filep: open file to /dev/sgx
That's
@encl: enclave pointer
or so.
> + * @arg: userspace pointer to a struct sgx_enclave_create instance
> + *
> + * Allocate kernel data structures for a new enclave and execute ECREATE after
> + * verifying the correctness of the provided SECS.
> + *
> + * Note, enforcement of restricted and disallowed attributes is deferred until
> + * sgx_ioc_enclave_init(), only the architectural correctness of the SECS is
> + * checked by sgx_ioc_enclave_create().
Well, I don't see that checking. Where is it?
> + *
> + * Return:
> + * 0 on success,
> + * -errno otherwise
> + */
> +static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg)
> +{
> + struct sgx_enclave_create ecreate;
> + struct page *secs_page;
> + struct sgx_secs *secs;
> + int ret;
> +
> + if (copy_from_user(&ecreate, arg, sizeof(ecreate)))
> + return -EFAULT;
> +
> + secs_page = alloc_page(GFP_KERNEL);
> + if (!secs_page)
> + return -ENOMEM;
> +
> + secs = kmap(secs_page);
> + if (copy_from_user(secs, (void __user *)ecreate.src, sizeof(*secs))) {
> + ret = -EFAULT;
> + goto out;
> + }
> +
> + ret = sgx_encl_create(encl, secs);
> +
> +out:
> + kunmap(secs_page);
> + __free_page(secs_page);
> + return ret;
> +}
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-06-26 9:14 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 22:08 [PATCH v33 00/21] Intel SGX foundations Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 01/21] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-06-22 17:37 ` Borislav Petkov
2020-06-25 1:25 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 02/21] x86/cpufeatures: x86/msr: Add Intel SGX Launch Control " Jarkko Sakkinen
2020-06-24 13:04 ` Borislav Petkov
2020-06-24 14:34 ` Sean Christopherson
2020-06-25 1:28 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 03/21] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-06-25 8:59 ` Borislav Petkov
2020-06-25 15:34 ` Sean Christopherson
2020-06-25 16:49 ` Borislav Petkov
2020-06-25 20:52 ` Jarkko Sakkinen
2020-06-25 21:11 ` Borislav Petkov
2020-06-26 13:34 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 04/21] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 05/21] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 06/21] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 07/21] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 08/21] x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections Jarkko Sakkinen
2020-06-25 10:14 ` Borislav Petkov
2020-06-25 20:11 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 09/21] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Jarkko Sakkinen
2020-06-25 17:06 ` Borislav Petkov
2020-06-25 20:55 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 10/21] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen
2020-06-25 17:14 ` Borislav Petkov
2020-06-25 17:30 ` Matthew Wilcox
2020-06-25 18:06 ` Sean Christopherson
2020-06-25 22:40 ` Jarkko Sakkinen
2020-06-25 22:26 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 11/21] x86/sgx: Linux Enclave Driver Jarkko Sakkinen
2020-06-25 17:23 ` Borislav Petkov
2020-06-25 18:34 ` Sean Christopherson
2020-06-25 18:45 ` Borislav Petkov
2020-06-26 14:19 ` Jarkko Sakkinen
2020-06-25 20:21 ` Jarkko Sakkinen
2020-06-25 20:25 ` Borislav Petkov
2020-06-26 13:40 ` Jarkko Sakkinen
2020-06-25 18:53 ` Borislav Petkov
2020-06-26 14:17 ` Jarkko Sakkinen
2020-06-26 9:14 ` Borislav Petkov [this message]
2020-06-26 14:16 ` Sean Christopherson
2020-06-26 14:20 ` Borislav Petkov
2020-07-03 23:04 ` Jarkko Sakkinen
2020-07-03 3:09 ` Jarkko Sakkinen
2020-06-26 15:34 ` Borislav Petkov
2020-07-04 0:13 ` Jarkko Sakkinen
2020-10-26 21:26 ` Dave Hansen
2020-10-27 1:52 ` Jarkko Sakkinen
2020-10-27 10:05 ` Borislav Petkov
2020-10-27 15:20 ` Dave Hansen
2020-10-27 15:37 ` Borislav Petkov
2020-06-27 17:43 ` Borislav Petkov
2020-06-29 15:27 ` Sean Christopherson
2020-06-29 15:37 ` Borislav Petkov
2020-07-04 1:43 ` Jarkko Sakkinen
2020-07-07 1:38 ` Sean Christopherson
2020-07-07 3:29 ` Jarkko Sakkinen
2020-07-04 1:42 ` Jarkko Sakkinen
2020-07-02 3:59 ` Sean Christopherson
2020-07-04 3:31 ` Jarkko Sakkinen
2020-09-02 3:06 ` Haitao Huang
2020-09-02 16:10 ` Sean Christopherson
2020-09-02 18:40 ` Haitao Huang
2020-09-04 12:01 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 12/21] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation Jarkko Sakkinen
2020-06-29 16:02 ` Borislav Petkov
2020-06-29 22:04 ` Sean Christopherson
2020-06-30 8:49 ` Borislav Petkov
2020-06-30 14:20 ` Sean Christopherson
2020-06-30 17:13 ` Andy Lutomirski
2020-07-02 20:47 ` Dr. Greg
2020-07-03 2:43 ` Jarkko Sakkinen
2020-07-03 2:38 ` Jarkko Sakkinen
2020-07-03 2:32 ` Jarkko Sakkinen
2020-07-03 2:55 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 13/21] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 14/21] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 15/21] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-06-29 17:10 ` Borislav Petkov
2020-06-30 6:00 ` Sean Christopherson
2020-06-30 8:41 ` Borislav Petkov
2020-06-30 14:55 ` Sean Christopherson
2020-06-30 16:48 ` Andy Lutomirski
2020-06-30 17:23 ` Sean Christopherson
2020-07-02 12:52 ` Thomas Gleixner
2020-06-17 22:08 ` [PATCH v33 16/21] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 17/21] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 18/21] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 19/21] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 20/21] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 21/21] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
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