You get entity from "amd_sched_select_entity", and after that the spinlock of RQ backing this entity is also unlocked, But immediately you call "sched_job = amd_sched_entity_peek_job(entity)", keep in mind that this point the "entity" may Already be a wild pointer, since above "sched_select_entity' unlock the RQ's spinlock For gpu reset feature, it's more complicated, because in run_job() routine we need check entity's guilty pointer, but that time The entity from sched_job->s_entity may also already a wild pointer Hah, headache BR Monk -----Original Message----- From: Koenig, Christian Sent: 2017å¹´10æ??24æ?¥ 18:13 To: Liu, Monk <Monk.Liu at amd.com>; Zhou, David(ChunMing) <David1.Zhou at amd.com>; amd-gfx at lists.freedesktop.org Subject: Re: [PATCH] drm/amd/scheduler: fix one used-after-free case for job->s_entity I thought we had fixed that one as well. The entity isn't accessed any more after amd_sched_entity_pop_job(). Regards, Christian. Am 24.10.2017 um 12:06 schrieb Liu, Monk: > Christian > > Actually there are more wild pointer issue for entity in scheduler's main routine .... > > > See the message I replied to David > > BR Monk > > -----Original Message----- > From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf > Of Christian K?nig > Sent: 2017å¹´10æ??24æ?¥ 18:01 > To: Zhou, David(ChunMing) <David1.Zhou at amd.com>; > amd-gfx at lists.freedesktop.org > Subject: Re: [PATCH] drm/amd/scheduler: fix one used-after-free case > for job->s_entity > > 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 > > _______________________________________________ > amd-gfx mailing list > amd-gfx at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
