From: "zhangfei.gao@foxmail.com" <zhangfei.gao@foxmail.com>
To: Fenghua Yu <fenghua.yu@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>,
Joerg Roedel <joro@8bytes.org>,
jean-philippe <jean-philippe@linaro.org>,
Ravi V Shankar <ravi.v.shankar@intel.com>,
Tony Luck <tony.luck@intel.com>, Ashok Raj <ashok.raj@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Dave Hansen <dave.hansen@linux.intel.com>, x86 <x86@kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
iommu <iommu@lists.linux-foundation.org>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH v4 05/11] iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit
Date: Fri, 15 Apr 2022 18:14:09 +0800 [thread overview]
Message-ID: <tencent_960E0647C06CE7A9893545A5AD345876240A@qq.com> (raw)
Message-ID: <99bcb9f5-4776-9c40-a776-cdecfa9e1010@foxmail.com> (raw)
In-Reply-To: <YllADL6uMoLllzQo@fyu1.sc.intel.com>
On 2022/4/15 下午5:51, Fenghua Yu wrote:
> On Thu, Apr 14, 2022 at 06:08:09PM +0800, zhangfei.gao@foxmail.com wrote:
>> On 2022/4/12 下午11:35, zhangfei.gao@foxmail.com wrote:
>>> Hi, Fenghua
>>>
>>> On 2022/4/12 下午9:41, Fenghua Yu wrote:
>>>> Hi, Zhangfei,
>>>>
>>>> On Tue, Apr 12, 2022 at 03:04:09PM +0800, zhangfei.gao@foxmail.com
>>>> wrote:
>>>>> On 2022/4/11 下午10:52, Dave Hansen wrote:
>>>>>> On 4/11/22 07:44, zhangfei.gao@foxmail.com wrote:
>>>>>>> On 2022/4/11 下午10:36, Dave Hansen wrote:
>>>>>>>> On 4/11/22 07:20, zhangfei.gao@foxmail.com wrote:
>>> Agree with Dave, I think user space should not be broken.
>>>
>>> Thanks
>> Any plan about this regression?
>> Currently I need this patch to workaround the issue.
>>
>> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
>> b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
>> index 22ddd05bbdcd..2d74ac53d11c 100644
>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
>> @@ -4,6 +4,7 @@
>> */
>>
>> #include <linux/mm.h>
>> +#include <linux/sched/mm.h>
>> #include <linux/mmu_context.h>
>> #include <linux/mmu_notifier.h>
>> #include <linux/slab.h>
>> @@ -363,6 +364,7 @@ arm_smmu_sva_bind(struct device *dev, struct mm_struct
>> *mm, void *drvdata)
>>
>> mutex_lock(&sva_lock);
>> handle = __arm_smmu_sva_bind(dev, mm);
>> + mmget(mm);
>> mutex_unlock(&sva_lock);
>> return handle;
>> }
>> @@ -377,6 +379,7 @@ void arm_smmu_sva_unbind(struct iommu_sva *handle)
>> arm_smmu_mmu_notifier_put(bond->smmu_mn);
>> kfree(bond);
>> }
>> + mmput(bond->mm);
>> mutex_unlock(&sva_lock);
>> }
> Could you please review and/or test this patch? It's supposed to fix
> the PASID issue on both ARM and X86.
>
> From a6444e1e5bd8076f5e5c5e950d3192de327f0c9c Mon Sep 17 00:00:00 2001
> From: Fenghua Yu <fenghua.yu@intel.com>
> Date: Fri, 15 Apr 2022 00:51:33 -0700
> Subject: [RFC PATCH] iommu/sva: Fix PASID use-after-free issue
>
> A PASID might be still used even though it is freed on mm exit.
>
> process A:
> sva_bind();
> ioasid_alloc() = N; // Get PASID N for the mm
> fork(): // spawn process B
> exit();
> ioasid_free(N);
>
> process B:
> device uses PASID N -> failure
> sva_unbind();
>
> Dave Hansen suggests to take a refcount on the mm whenever binding the
> PASID to a device and drop the refcount on unbinding. The mm won't be
> dropped if the PASID is still bound to it.
>
> Fixes: 701fac40384f ("iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit")
>
> Reported-by: Zhangfei Gao <zhangfei.gao@foxmail.com>
> Suggested-by: Dave Hansen" <dave.hansen@linux.intel.com>
> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 6 ++++++
> drivers/iommu/intel/svm.c | 4 ++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> index 22ddd05bbdcd..3fcb842a0df0 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> @@ -7,6 +7,7 @@
> #include <linux/mmu_context.h>
> #include <linux/mmu_notifier.h>
> #include <linux/slab.h>
> +#include <linux/sched/mm.h>
>
> #include "arm-smmu-v3.h"
> #include "../../iommu-sva-lib.h"
> @@ -363,6 +364,9 @@ arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
>
> mutex_lock(&sva_lock);
> handle = __arm_smmu_sva_bind(dev, mm);
> + /* Take an mm refcount on a successful bind. */
> + if (!IS_ERR(handle))
> + mmget(mm);
> mutex_unlock(&sva_lock);
> return handle;
> }
> @@ -372,6 +376,8 @@ void arm_smmu_sva_unbind(struct iommu_sva *handle)
> struct arm_smmu_bond *bond = sva_to_bond(handle);
>
> mutex_lock(&sva_lock);
> + /* Drop an mm refcount. */
> + mmput(bond->mm);
> if (refcount_dec_and_test(&bond->refs)) {
> list_del(&bond->list);
> arm_smmu_mmu_notifier_put(bond->smmu_mn);
> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> index 23a38763c1d1..345a0d5d7922 100644
> --- a/drivers/iommu/intel/svm.c
> +++ b/drivers/iommu/intel/svm.c
> @@ -403,6 +403,8 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
> goto free_sdev;
>
> list_add_rcu(&sdev->list, &svm->devs);
> + /* Take an mm refcount on binding mm. */
> + mmget(mm);
> success:
> return &sdev->sva;
>
> @@ -465,6 +467,8 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
> kfree(svm);
> }
> }
> + /* Drop an mm reference on unbinding mm. */
> + mmput(mm);
> }
> out:
> return ret;
This patch can not be applied on 5.18-rc2 for intel part.
It should work for arm.
In fact I have a similar patch at hand but pending since I found an issue.
I start & stop nginx via this cmd.
//start
sudo sbin/nginx // this alloc an ioasid=1
//stop
sudo sbin/nginx -s quit // this does not free ioasid=1, but still
alloc ioasid=2.
So ioasid will keep allocated but not freed if continue start/stop
nginx, though not impact the nginx function.
stop nginx with -s quit still calls
src/core/nginx.c
main -> ngx_ssl_init -> openssl engine: bind_fn -> ... -> alloc asid
But openssl engine: ENGINE_free is not called
Still in checking nginx code.
Or do you test with nginx?
Thanks
next prev parent reply other threads:[~2022-04-15 10:14 UTC|newest]
Thread overview: 113+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-07 23:02 [PATCH v4 00/11] Re-enable ENQCMD and PASID MSR Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 01/11] iommu/sva: Rename CONFIG_IOMMU_SVA_LIB to CONFIG_IOMMU_SVA Fenghua Yu
2022-02-08 2:39 ` Lu Baolu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 02/11] mm: Change CONFIG option for mm->pasid field Fenghua Yu
2022-02-08 2:40 ` Lu Baolu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 03/11] iommu/ioasid: Introduce a helper to check for valid PASIDs Fenghua Yu
2022-02-08 2:40 ` Lu Baolu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 04/11] kernel/fork: Initialize mm's PASID Fenghua Yu
2022-02-14 17:23 ` Thomas Gleixner
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 05/11] iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit Fenghua Yu
2022-02-08 2:41 ` Lu Baolu
2022-02-08 15:01 ` Fenghua Yu
2022-02-10 3:16 ` Jacob Pan
2022-02-10 16:27 ` Fenghua Yu
2022-02-10 17:24 ` Luck, Tony
2022-02-10 18:31 ` Fenghua Yu
2022-02-10 23:52 ` Fenghua Yu
2022-02-10 18:49 ` Jacob Pan
2022-02-10 23:15 ` Fenghua Yu
2022-02-11 22:00 ` Dave Hansen
2022-02-14 17:24 ` Thomas Gleixner
2022-02-15 9:55 ` Joerg Roedel
[not found] ` <tencent_F6830A1196DB4C6A904D7C691F0D961D1108@qq.com>
2022-04-11 14:10 ` Dave Hansen
2022-04-11 14:20 ` zhangfei.gao
2022-04-11 14:36 ` Dave Hansen
2022-04-11 14:44 ` zhangfei.gao
2022-04-11 14:52 ` Dave Hansen
2022-04-11 15:13 ` zhangfei.gao
2022-04-12 7:04 ` zhangfei.gao
2022-04-12 13:41 ` Fenghua Yu
2022-04-12 14:39 ` Dave Hansen
2022-04-15 9:59 ` Fenghua Yu
2022-04-12 15:35 ` zhangfei.gao
2022-04-14 10:08 ` zhangfei.gao
2022-04-15 9:51 ` Fenghua Yu
[not found] ` <99bcb9f5-4776-9c40-a776-cdecfa9e1010@foxmail.com>
2022-04-15 10:14 ` zhangfei.gao [this message]
2022-04-15 10:50 ` Fenghua Yu
2022-04-15 11:52 ` zhangfei.gao
2022-04-15 12:37 ` Fenghua Yu
2022-04-16 1:30 ` zhangfei.gao
2022-04-15 19:07 ` Fenghua Yu
2022-04-15 21:00 ` Jacob Pan
2022-04-16 1:43 ` zhangfei.gao
2022-04-18 18:14 ` Jacob Pan
2022-04-19 1:02 ` zhangfei.gao
2022-04-18 6:34 ` Tian, Kevin
2022-04-18 18:11 ` Jacob Pan
2022-04-20 16:45 ` Jean-Philippe Brucker
2022-04-21 6:47 ` zhangfei.gao
2022-04-22 9:03 ` zhangfei.gao
2022-04-22 10:11 ` Jean-Philippe Brucker
2022-04-22 13:15 ` zhangfei.gao
2022-04-22 15:50 ` Jean-Philippe Brucker
2022-04-23 11:13 ` zhangfei.gao
2022-04-24 2:58 ` Zhangfei Gao
2022-04-24 9:52 ` Zhangfei Gao
2022-04-25 13:53 ` Jean-Philippe Brucker
2022-04-25 14:18 ` Dave Hansen
2022-04-25 14:26 ` Jean-Philippe Brucker
2022-04-25 15:34 ` Jacob Pan
2022-04-25 16:13 ` Jean-Philippe Brucker
2022-04-25 22:32 ` Jacob Pan
2022-04-26 4:20 ` Fenghua Yu
2022-04-26 5:04 ` Zhangfei Gao
2022-04-28 0:54 ` Fenghua Yu
2022-04-28 8:43 ` Jean-Philippe Brucker
2022-04-28 15:09 ` Dave Hansen
2022-04-28 15:28 ` Fenghua Yu
2022-04-28 15:42 ` Dave Hansen
2022-04-28 16:01 ` Jean-Philippe Brucker
2022-04-28 16:35 ` Dave Hansen
2022-04-26 4:28 ` Zhangfei Gao
2022-04-26 4:36 ` Fenghua Yu
2022-04-26 5:19 ` Zhangfei Gao
2022-04-25 15:55 ` Dave Hansen
2022-04-25 16:40 ` Jean-Philippe Brucker
2022-04-26 15:27 ` Dave Hansen
2022-04-26 16:48 ` Jean-Philippe Brucker
2022-04-26 23:31 ` Dave Hansen
2022-04-28 8:39 ` Jean-Philippe Brucker
2022-04-29 7:53 ` Baolu Lu
2022-04-29 13:51 ` Fenghua Yu
2022-04-29 14:34 ` Jean-Philippe Brucker
2022-04-29 22:19 ` Fenghua Yu
2022-04-30 7:33 ` Baolu Lu
2022-05-03 7:49 ` Jean-Philippe Brucker
2022-05-06 5:36 ` Baolu Lu
2022-04-12 14:36 ` Dave Hansen
2022-04-12 15:10 ` Jean-Philippe Brucker
2022-04-12 15:35 ` Dave Hansen
2022-04-13 11:14 ` Lu Baolu
2022-04-25 2:57 ` zhangfei.gao
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 06/11] x86/fpu: Clear PASID when copying fpstate Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 07/11] sched: Define and initialize a flag to identify valid PASID in the task Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Peter Zijlstra
2022-02-07 23:02 ` [PATCH v4 08/11] x86/traps: Demand-populate PASID MSR via #GP Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 09/11] x86/cpufeatures: Re-enable ENQCMD Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 10/11] tools/objtool: Check for use of the ENQCMD instruction in the kernel Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-03-09 7:55 ` [tip: x86/core] " tip-bot2 for Fenghua Yu
2022-03-15 10:44 ` tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 11/11] docs: x86: Change documentation for SVA (Shared Virtual Addressing) Fenghua Yu
2022-02-14 17:25 ` Thomas Gleixner
2022-02-15 10:54 ` [tip: x86/pasid] Documentation/x86: Update " tip-bot2 for Fenghua Yu
2022-02-11 20:04 ` [PATCH v4 00/11] Re-enable ENQCMD and PASID MSR Fenghua Yu
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