Quoting Chris Wilson (2018-01-06 10:56:18) > When we retire a signaled fence, we free the dependency tree. However, > we skip clearing the list so that if we then try to adjust the priority > of the signaled fence, we may walk the list of freed dependencies. > > [ 3083.156757] ================================================================== > [ 3083.156806] BUG: KASAN: use-after-free in execlists_schedule+0x199/0x660 [i915] > [ 3083.156810] Read of size 8 at addr ffff8806bf20f400 by task Xorg/831 > > [ 3083.156815] CPU: 0 PID: 831 Comm: Xorg Not tainted 4.15.0-rc6-no-psn+ #1 > [ 3083.156817] Hardware name: Notebook N24_25BU/N24_25BU, BIOS 5.12 02/17/2017 > [ 3083.156818] Call Trace: > [ 3083.156823] dump_stack+0x5c/0x7a > [ 3083.156827] print_address_description+0x6b/0x290 > [ 3083.156830] kasan_report+0x28f/0x380 > [ 3083.156872] ? execlists_schedule+0x199/0x660 [i915] > [ 3083.156914] execlists_schedule+0x199/0x660 [i915] > [ 3083.156956] ? intel_crtc_atomic_check+0x146/0x4e0 [i915] > [ 3083.156997] ? execlists_submit_request+0xe0/0xe0 [i915] > [ 3083.157038] ? i915_vma_misplaced.part.4+0x25/0xb0 [i915] > [ 3083.157079] ? __i915_vma_do_pin+0x7c8/0xc80 [i915] > [ 3083.157121] ? intel_atomic_state_alloc+0x44/0x60 [i915] > [ 3083.157130] ? drm_atomic_helper_page_flip+0x3e/0xb0 [drm_kms_helper] > [ 3083.157145] ? drm_mode_page_flip_ioctl+0x7d2/0x850 [drm] > [ 3083.157159] ? drm_ioctl_kernel+0xa7/0xf0 [drm] > [ 3083.157172] ? drm_ioctl+0x45b/0x560 [drm] > [ 3083.157211] i915_gem_object_wait_priority+0x14c/0x2c0 [i915] > [ 3083.157251] ? i915_gem_get_aperture_ioctl+0x150/0x150 [i915] > [ 3083.157290] ? i915_vma_pin_fence+0x1d8/0x320 [i915] > [ 3083.157331] ? intel_pin_and_fence_fb_obj+0x175/0x250 [i915] > [ 3083.157372] ? intel_rotation_info_size+0x60/0x60 [i915] > [ 3083.157413] ? intel_link_compute_m_n+0x80/0x80 [i915] > [ 3083.157428] ? drm_dev_printk+0x1b0/0x1b0 [drm] > [ 3083.157443] ? drm_dev_printk+0x1b0/0x1b0 [drm] > [ 3083.157485] intel_prepare_plane_fb+0x2f8/0x5a0 [i915] > [ 3083.157527] ? intel_crtc_get_vblank_counter+0x80/0x80 [i915] > [ 3083.157536] drm_atomic_helper_prepare_planes+0xa0/0x1c0 [drm_kms_helper] > [ 3083.157587] intel_atomic_commit+0x12e/0x4e0 [i915] > [ 3083.157605] drm_atomic_helper_page_flip+0xa2/0xb0 [drm_kms_helper] > [ 3083.157621] drm_mode_page_flip_ioctl+0x7d2/0x850 [drm] > [ 3083.157638] ? drm_mode_cursor2_ioctl+0x10/0x10 [drm] > [ 3083.157652] ? drm_lease_owner+0x1a/0x30 [drm] > [ 3083.157668] ? drm_mode_cursor2_ioctl+0x10/0x10 [drm] > [ 3083.157681] drm_ioctl_kernel+0xa7/0xf0 [drm] > [ 3083.157696] drm_ioctl+0x45b/0x560 [drm] > [ 3083.157711] ? drm_mode_cursor2_ioctl+0x10/0x10 [drm] > [ 3083.157725] ? drm_getstats+0x20/0x20 [drm] > [ 3083.157729] ? timerqueue_del+0x49/0x80 > [ 3083.157732] ? __remove_hrtimer+0x62/0xb0 > [ 3083.157735] ? hrtimer_try_to_cancel+0x173/0x210 > [ 3083.157738] do_vfs_ioctl+0x13b/0x880 > [ 3083.157741] ? ioctl_preallocate+0x140/0x140 > [ 3083.157744] ? _raw_spin_unlock_irq+0xe/0x30 > [ 3083.157746] ? do_setitimer+0x234/0x370 > [ 3083.157750] ? SyS_setitimer+0x19e/0x1b0 > [ 3083.157752] ? SyS_alarm+0x140/0x140 > [ 3083.157755] ? __rcu_read_unlock+0x66/0x80 > [ 3083.157757] ? __fget+0xc4/0x100 > [ 3083.157760] SyS_ioctl+0x74/0x80 > [ 3083.157763] entry_SYSCALL_64_fastpath+0x1a/0x7d > [ 3083.157765] RIP: 0033:0x7f6135d0c6a7 > [ 3083.157767] RSP: 002b:00007fff01451888 EFLAGS: 00003246 ORIG_RAX: 0000000000000010 > [ 3083.157769] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f6135d0c6a7 > [ 3083.157771] RDX: 00007fff01451950 RSI: 00000000c01864b0 RDI: 000000000000000c > [ 3083.157772] RBP: 00007f613076f600 R08: 0000000000000001 R09: 0000000000000000 > [ 3083.157773] R10: 0000000000000060 R11: 0000000000003246 R12: 0000000000000000 > [ 3083.157774] R13: 0000000000000060 R14: 000000000000001b R15: 0000000000000060 > > [ 3083.157779] Allocated by task 831: > [ 3083.157783] kmem_cache_alloc+0xc0/0x200 > [ 3083.157822] i915_gem_request_await_dma_fence+0x2c4/0x5d0 [i915] > [ 3083.157861] i915_gem_request_await_object+0x321/0x370 [i915] > [ 3083.157900] i915_gem_do_execbuffer+0x1165/0x19c0 [i915] > [ 3083.157937] i915_gem_execbuffer2+0x1ad/0x550 [i915] > [ 3083.157950] drm_ioctl_kernel+0xa7/0xf0 [drm] > [ 3083.157962] drm_ioctl+0x45b/0x560 [drm] > [ 3083.157964] do_vfs_ioctl+0x13b/0x880 > [ 3083.157966] SyS_ioctl+0x74/0x80 > [ 3083.157968] entry_SYSCALL_64_fastpath+0x1a/0x7d > > [ 3083.157971] Freed by task 831: > [ 3083.157973] kmem_cache_free+0x77/0x220 > [ 3083.158012] i915_gem_request_retire+0x72c/0xa70 [i915] > [ 3083.158051] i915_gem_request_alloc+0x1e9/0x8b0 [i915] > [ 3083.158089] i915_gem_do_execbuffer+0xa96/0x19c0 [i915] > [ 3083.158127] i915_gem_execbuffer2+0x1ad/0x550 [i915] > [ 3083.158140] drm_ioctl_kernel+0xa7/0xf0 [drm] > [ 3083.158153] drm_ioctl+0x45b/0x560 [drm] > [ 3083.158155] do_vfs_ioctl+0x13b/0x880 > [ 3083.158156] SyS_ioctl+0x74/0x80 > [ 3083.158158] entry_SYSCALL_64_fastpath+0x1a/0x7d > > [ 3083.158162] The buggy address belongs to the object at ffff8806bf20f400 > which belongs to the cache i915_dependency of size 64 > [ 3083.158166] The buggy address is located 0 bytes inside of > 64-byte region [ffff8806bf20f400, ffff8806bf20f440) > [ 3083.158168] The buggy address belongs to the page: > [ 3083.158171] page:00000000d43decc4 count:1 mapcount:0 mapping: (null) index:0x0 > [ 3083.158174] flags: 0x17ffe0000000100(slab) > [ 3083.158179] raw: 017ffe0000000100 0000000000000000 0000000000000000 0000000180200020 > [ 3083.158182] raw: ffffea001afc16c0 0000000500000005 ffff880731b881c0 0000000000000000 > [ 3083.158184] page dumped because: kasan: bad access detected > > [ 3083.158187] Memory state around the buggy address: > [ 3083.158190] ffff8806bf20f300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > [ 3083.158192] ffff8806bf20f380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > [ 3083.158195] >ffff8806bf20f400: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > [ 3083.158196] ^ > [ 3083.158199] ffff8806bf20f480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > [ 3083.158201] ffff8806bf20f500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > [ 3083.158203] ================================================================== > > Reported-by: Alexandru Chirvasitu <achirvasub@xxxxxxxxx> > Reported-by: Mike Keehan <mike@xxxxxxxxxx> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104436 > Fixes: 1f181225f8ec ("drm/i915/execlists: Keep request->priority for its lifetime") > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Alexandru Chirvasitu <achirvasub@xxxxxxxxx> > Cc: Michał Winiarski <michal.winiarski@xxxxxxxxx> > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> Preemptive, Tested-by: Alexandru Chirvasitu <achirvasub@xxxxxxxxx> -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
