From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
linux-sgx@vger.kernel.org, akpm@linux-foundation.org,
dave.hansen@intel.com, nhorman@redhat.com, npmccallum@redhat.com,
haitao.huang@intel.com, andriy.shevchenko@linux.intel.com,
tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de,
josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com,
rientjes@google.com, cedric.xing@intel.com,
puiterwijk@redhat.com, linux-security-module@vger.kernel.org,
Suresh Siddha <suresh.b.siddha@intel.com>,
Jethro Beekman <jethro@fortanix.com>,
Haitao Huang <haitao.huang@linux.intel.com>,
Chunyang Hui <sanqian.hcy@antfin.com>,
Jordan Hand <jorhand@linux.microsoft.com>,
Seth Moore <sethmo@google.com>
Subject: Re: [PATCH v30 10/20] x86/sgx: Linux Enclave Driver
Date: Fri, 22 May 2020 22:39:14 +0300 [thread overview]
Message-ID: <20200522193914.GF10319@linux.intel.com> (raw)
In-Reply-To: <20200521191236.GA23043@linux.intel.com>
On Thu, May 21, 2020 at 12:12:36PM -0700, Sean Christopherson wrote:
> On Fri, May 15, 2020 at 03:44:00AM +0300, Jarkko Sakkinen wrote:
> > +long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
> > +{
> > + struct sgx_encl *encl = filep->private_data;
> > + int ret, encl_flags;
> > +
> > + encl_flags = atomic_fetch_or(SGX_ENCL_IOCTL, &encl->flags);
> > + if (encl_flags & SGX_ENCL_IOCTL)
> > + return -EBUSY;
> > +
> > + if (encl_flags & SGX_ENCL_DEAD)
> > + return -EFAULT;
>
> Returning immediately is wrong as it leaves SGX_ENCL_IOCTL set. This results
> in the application seeing -EBUSY on future ioctls() instead of -EFAULT. Can be
> fixed as below. Do you want me to send a formal patch on linux-sgx?
>
> diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
> index 77757a74644d..df35a79e915c 100644
> --- a/arch/x86/kernel/cpu/sgx/ioctl.c
> +++ b/arch/x86/kernel/cpu/sgx/ioctl.c
> @@ -751,8 +751,10 @@ long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
> if (encl_flags & SGX_ENCL_IOCTL)
> return -EBUSY;
>
> - if (encl_flags & SGX_ENCL_DEAD)
> - return -EFAULT;
> + if (encl_flags & SGX_ENCL_DEAD) {
> + ret = -EFAULT;
> + goto out;
> + }
>
> switch (cmd) {
> case SGX_IOC_ENCLAVE_CREATE:
> @@ -772,6 +774,7 @@ long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
> break;
> }
>
> +out:
> atomic_andnot(SGX_ENCL_IOCTL, &encl->flags);
>
> return ret;
>
>
> > +
> > + switch (cmd) {
> > + case SGX_IOC_ENCLAVE_CREATE:
> > + ret = sgx_ioc_enclave_create(encl, (void __user *)arg);
> > + break;
> > + case SGX_IOC_ENCLAVE_ADD_PAGES:
> > + ret = sgx_ioc_enclave_add_pages(encl, (void __user *)arg);
> > + break;
> > + case SGX_IOC_ENCLAVE_INIT:
> > + ret = sgx_ioc_enclave_init(encl, (void __user *)arg);
> > + break;
> > + default:
> > + ret = -ENOIOCTLCMD;
> > + break;
> > + }
> > +
> > + atomic_andnot(SGX_ENCL_IOCTL, &encl->flags);
> > +
> > + return ret;
> > +}
Thanks. Fixed in my tree:
v31:
* Unset SGX_ENCL_IOCTL in the error path of checking encl->flags in order
to prevent leaving it set, and thus block any further ioctl calls.
* Added missing cleanup_srcu_struct() call to sgx_encl_release().
* Take encl->lock in sgx_encl_add_page() in order to prevent races with
the page reclaimer.
/Jarkko
next prev parent reply other threads:[~2020-05-22 19:39 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-15 0:43 [PATCH v30 00/20] Intel SGX foundations Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 01/20] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-05-20 12:16 ` Borislav Petkov
2020-05-20 14:00 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 02/20] x86/cpufeatures: x86/msr: Intel SGX Launch Control " Jarkko Sakkinen
2020-05-20 12:23 ` Borislav Petkov
2020-05-20 14:04 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 03/20] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 04/20] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-05-20 18:47 ` Borislav Petkov
2020-05-20 21:04 ` Sean Christopherson
2020-05-22 15:54 ` Jarkko Sakkinen
2020-05-22 16:13 ` Sean Christopherson
2020-05-22 19:50 ` Jarkko Sakkinen
2020-05-25 8:20 ` Borislav Petkov
2020-05-27 19:43 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 05/20] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 06/20] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 07/20] x86/sgx: Enumerate and track EPC sections Jarkko Sakkinen
2020-05-25 9:23 ` Borislav Petkov
2020-05-27 3:56 ` Sean Christopherson
2020-05-27 20:35 ` Borislav Petkov
2020-05-28 7:36 ` Jarkko Sakkinen
2020-05-28 5:25 ` Jarkko Sakkinen
2020-05-28 5:35 ` Jarkko Sakkinen
2020-05-28 6:14 ` Jarkko Sakkinen
2020-05-28 6:16 ` Jarkko Sakkinen
2020-05-28 5:13 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 08/20] x86/sgx: Add functions to allocate and free EPC pages Jarkko Sakkinen
2020-05-26 12:52 ` Borislav Petkov
2020-05-27 4:21 ` Sean Christopherson
2020-05-27 20:46 ` Borislav Petkov
2020-05-28 0:52 ` Sean Christopherson
2020-05-28 6:51 ` Jarkko Sakkinen
2020-05-28 1:23 ` Jarkko Sakkinen
2020-05-28 1:36 ` Sean Christopherson
2020-05-28 6:52 ` Jarkko Sakkinen
2020-05-28 17:16 ` Borislav Petkov
2020-05-28 17:19 ` Sean Christopherson
2020-05-28 17:27 ` Borislav Petkov
2020-05-28 17:34 ` Sean Christopherson
2020-05-28 19:07 ` Jarkko Sakkinen
2020-05-28 19:59 ` Sean Christopherson
2020-05-29 3:28 ` Jarkko Sakkinen
2020-05-29 3:37 ` Sean Christopherson
2020-05-29 5:07 ` Jarkko Sakkinen
2020-05-29 8:12 ` Jarkko Sakkinen
2020-05-29 8:13 ` Jarkko Sakkinen
2020-05-29 3:38 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 09/20] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen
2020-05-29 12:10 ` Borislav Petkov
2020-05-29 18:18 ` Jarkko Sakkinen
2020-05-29 18:28 ` Dave Hansen
2020-05-31 23:12 ` Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 10/20] x86/sgx: Linux Enclave Driver Jarkko Sakkinen
2020-05-21 19:12 ` Sean Christopherson
2020-05-22 19:26 ` Jarkko Sakkinen
2020-05-22 19:39 ` Jarkko Sakkinen [this message]
2020-05-22 3:33 ` Sean Christopherson
2020-05-15 0:44 ` [PATCH v30 11/20] x86/sgx: Add provisioning Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 12/20] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-05-22 6:58 ` Sean Christopherson
2020-05-22 19:57 ` Jarkko Sakkinen
2020-05-22 21:52 ` Sean Christopherson
2020-05-22 7:15 ` Sean Christopherson
2020-05-22 19:47 ` Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 13/20] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 14/20] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 15/20] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 16/20] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 17/20] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 18/20] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 19/20] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 20/20] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
2020-05-16 8:57 ` [PATCH] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
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