From 5005c8514285ae4f28e862f8d91faaa2015e03a3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sat, 6 Jan 2018 10:56:18 +0000 Subject: drm/i915: Don't adjust priority on an already signaled fence MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reported-by: Mike Keehan 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 Cc: Alexandru Chirvasitu Cc: Michał Winiarski Cc: Joonas Lahtinen Cc: Tvrtko Ursulin Tested-by: Alexandru Chirvasitu Reviewed-by: Michał Winiarski Link: https://patchwork.freedesktop.org/patch/msgid/20180106105618.13532-1-chris@chris-wilson.co.uk (cherry picked from commit c218ee03b9315073ce43992792554dafa0626eb8) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/i915_gem.c | 2 +- drivers/gpu/drm/i915/intel_lrc.c | 3 +++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 18de6569d04a..5cfba89ed586 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -467,7 +467,7 @@ static void __fence_set_priority(struct dma_fence *fence, int prio) struct drm_i915_gem_request *rq; struct intel_engine_cs *engine; - if (!dma_fence_is_i915(fence)) + if (dma_fence_is_signaled(fence) || !dma_fence_is_i915(fence)) return; rq = to_request(fence); diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index d36e25607435..e71a8cd50498 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -974,6 +974,9 @@ static void execlists_schedule(struct drm_i915_gem_request *request, int prio) GEM_BUG_ON(prio == I915_PRIORITY_INVALID); + if (i915_gem_request_completed(request)) + return; + if (prio <= READ_ONCE(request->priotree.priority)) return; -- cgit v1.2.1