[PATCH] drm/amd/scheduler: fix one used-after-free case for job->s_entity

Christian K├Ânig ckoenig.leichtzumerken at gmail.com
Tue Oct 24 10:01:16 UTC 2017


Andrey already submitted a fix for this a few days ago.

Christian.

Am 24.10.2017 um 11:55 schrieb Chunming Zhou:
> The s_entity presented process could already be closed when calling amdgpu_job_free_cb.
> the s_entity will be buggy pointer after it's freed. See below calltrace:
>
> [  355.616964] ==================================================================
> [  355.617191] BUG: KASAN: use-after-free in amdgpu_job_free_cb+0x2f/0xc0 [amdgpu]
> [  355.617197] Read of size 8 at addr ffff88039d593c40 by task kworker/9:1/100
>
> [  355.617206] CPU: 9 PID: 100 Comm: kworker/9:1 Not tainted 4.13.0-custom #1
> [  355.617208] Hardware name: Gigabyte Technology Co., Ltd. Default string/X99P-SLI-CF, BIOS F23 07/22/2016
> [  355.617342] Workqueue: events amd_sched_job_finish [amdgpu]
> [  355.617344] Call Trace:
> [  355.617351]  dump_stack+0x63/0x8d
> [  355.617356]  print_address_description+0x70/0x290
> [  355.617474]  ? amdgpu_job_free_cb+0x2f/0xc0 [amdgpu]
> [  355.617477]  kasan_report+0x265/0x350
> [  355.617479]  __asan_load8+0x54/0x90
> [  355.617603]  amdgpu_job_free_cb+0x2f/0xc0 [amdgpu]
> [  355.617721]  amd_sched_job_finish+0x161/0x180 [amdgpu]
> [  355.617725]  process_one_work+0x2ab/0x700
> [  355.617727]  worker_thread+0x90/0x720
> [  355.617731]  kthread+0x18c/0x1e0
> [  355.617732]  ? process_one_work+0x700/0x700
> [  355.617735]  ? kthread_create_on_node+0xb0/0xb0
> [  355.617738]  ret_from_fork+0x25/0x30
>
> [  355.617742] Allocated by task 1347:
> [  355.617747]  save_stack_trace+0x1b/0x20
> [  355.617749]  save_stack+0x46/0xd0
> [  355.617751]  kasan_kmalloc+0xad/0xe0
> [  355.617753]  kmem_cache_alloc_trace+0xef/0x200
> [  355.617853]  amdgpu_driver_open_kms+0x98/0x290 [amdgpu]
> [  355.617883]  drm_open+0x38c/0x6e0 [drm]
> [  355.617908]  drm_stub_open+0x144/0x1b0 [drm]
> [  355.617911]  chrdev_open+0x180/0x320
> [  355.617913]  do_dentry_open+0x3a2/0x570
> [  355.617915]  vfs_open+0x86/0xe0
> [  355.617918]  path_openat+0x49e/0x1db0
> [  355.617919]  do_filp_open+0x11c/0x1a0
> [  355.617921]  do_sys_open+0x16f/0x2a0
> [  355.617923]  SyS_open+0x1e/0x20
> [  355.617926]  do_syscall_64+0xea/0x210
> [  355.617928]  return_from_SYSCALL_64+0x0/0x6a
>
> [  355.617931] Freed by task 1347:
> [  355.617934]  save_stack_trace+0x1b/0x20
> [  355.617936]  save_stack+0x46/0xd0
> [  355.617937]  kasan_slab_free+0x70/0xc0
> [  355.617939]  kfree+0x9d/0x1c0
> [  355.618038]  amdgpu_driver_postclose_kms+0x1bc/0x3e0 [amdgpu]
> [  355.618063]  drm_release+0x454/0x610 [drm]
> [  355.618065]  __fput+0x177/0x350
> [  355.618066]  ____fput+0xe/0x10
> [  355.618068]  task_work_run+0xa0/0xc0
> [  355.618070]  do_exit+0x456/0x1320
> [  355.618072]  do_group_exit+0x86/0x130
> [  355.618074]  SyS_exit_group+0x1d/0x20
> [  355.618076]  do_syscall_64+0xea/0x210
> [  355.618078]  return_from_SYSCALL_64+0x0/0x6a
>
> [  355.618081] The buggy address belongs to the object at ffff88039d593b80
>                  which belongs to the cache kmalloc-2048 of size 2048
> [  355.618085] The buggy address is located 192 bytes inside of
>                  2048-byte region [ffff88039d593b80, ffff88039d594380)
> [  355.618087] The buggy address belongs to the page:
> [  355.618091] page:ffffea000e756400 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
> [  355.618095] flags: 0x2ffff0000008100(slab|head)
> [  355.618099] raw: 02ffff0000008100 0000000000000000 0000000000000000 00000001000f000f
> [  355.618103] raw: ffffea000edb0600 0000000200000002 ffff8803bfc0ea00 0000000000000000
> [  355.618105] page dumped because: kasan: bad access detected
>
> [  355.618108] Memory state around the buggy address:
> [  355.618110]  ffff88039d593b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [  355.618113]  ffff88039d593b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> [  355.618116] >ffff88039d593c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> [  355.618117]                                            ^
> [  355.618120]  ffff88039d593c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> [  355.618122]  ffff88039d593d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> [  355.618124] ==================================================================
> [  355.618126] Disabling lock debugging due to kernel taint
>
> Change-Id: I8ff7122796b8cd16fc26e9c40e8d4c8153d67e0c
> Signed-off-by: Chunming Zhou <david1.zhou at amd.com>
> ---
>   drivers/gpu/drm/amd/scheduler/gpu_scheduler.c |  1 +
>   drivers/gpu/drm/amd/scheduler/gpu_scheduler.h | 27 ++++++++++++++-------------
>   2 files changed, 15 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
> index 007fdbd..8101ed7 100644
> --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
> +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
> @@ -535,6 +535,7 @@ int amd_sched_job_init(struct amd_sched_job *job,
>   	if (!job->s_fence)
>   		return -ENOMEM;
>   	job->id = atomic64_inc_return(&sched->job_id_count);
> +	job->priority = job->s_entity->rq - job->sched->sched_rq;
>   
>   	INIT_WORK(&job->finish_work, amd_sched_job_finish);
>   	INIT_LIST_HEAD(&job->node);
> diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
> index e21299c..8808eb1 100644
> --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
> +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
> @@ -77,6 +77,18 @@ struct amd_sched_fence {
>   	void                            *owner;
>   };
>   
> +enum amd_sched_priority {
> +	AMD_SCHED_PRIORITY_MIN,
> +	AMD_SCHED_PRIORITY_LOW = AMD_SCHED_PRIORITY_MIN,
> +	AMD_SCHED_PRIORITY_NORMAL,
> +	AMD_SCHED_PRIORITY_HIGH_SW,
> +	AMD_SCHED_PRIORITY_HIGH_HW,
> +	AMD_SCHED_PRIORITY_KERNEL,
> +	AMD_SCHED_PRIORITY_MAX,
> +	AMD_SCHED_PRIORITY_INVALID = -1,
> +	AMD_SCHED_PRIORITY_UNSET = -2
> +};
> +
>   struct amd_sched_job {
>   	struct amd_gpu_scheduler        *sched;
>   	struct amd_sched_entity         *s_entity;
> @@ -87,6 +99,7 @@ struct amd_sched_job {
>   	struct delayed_work		work_tdr;
>   	uint64_t			id;
>   	atomic_t karma;
> +	enum amd_sched_priority		priority;
>   };
>   
>   extern const struct dma_fence_ops amd_sched_fence_ops_scheduled;
> @@ -118,18 +131,6 @@ struct amd_sched_backend_ops {
>   	void (*free_job)(struct amd_sched_job *sched_job);
>   };
>   
> -enum amd_sched_priority {
> -	AMD_SCHED_PRIORITY_MIN,
> -	AMD_SCHED_PRIORITY_LOW = AMD_SCHED_PRIORITY_MIN,
> -	AMD_SCHED_PRIORITY_NORMAL,
> -	AMD_SCHED_PRIORITY_HIGH_SW,
> -	AMD_SCHED_PRIORITY_HIGH_HW,
> -	AMD_SCHED_PRIORITY_KERNEL,
> -	AMD_SCHED_PRIORITY_MAX,
> -	AMD_SCHED_PRIORITY_INVALID = -1,
> -	AMD_SCHED_PRIORITY_UNSET = -2
> -};
> -
>   /**
>    * One scheduler is implemented for each hardware ring
>   */
> @@ -183,7 +184,7 @@ void amd_sched_job_kickout(struct amd_sched_job *s_job);
>   static inline enum amd_sched_priority
>   amd_sched_get_job_priority(struct amd_sched_job *job)
>   {
> -	return (job->s_entity->rq - job->sched->sched_rq);
> +	return job->priority;
>   }
>   
>   #endif




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