================================================================== BUG: KASAN: slab-use-after-free in drm_atomic_helper_wait_for_vblanks.part.0+0x847/0x920 drivers/gpu/drm/drm_atomic_helper.c:1650 Read of size 1 at addr ffff888023d92c09 by task kworker/u16:23/24907 CPU: 2 PID: 24907 Comm: kworker/u16:23 Not tainted 6.6.0-rc5-syzkaller-00067-g8182d7a3f1b8 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Workqueue: events_unbound commit_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 drm_atomic_helper_wait_for_vblanks.part.0+0x847/0x920 drivers/gpu/drm/drm_atomic_helper.c:1650 drm_atomic_helper_wait_for_vblanks drivers/gpu/drm/drm_atomic_helper.c:1646 [inline] drm_atomic_helper_commit_tail+0xcb/0xf0 drivers/gpu/drm/drm_atomic_helper.c:1746 commit_tail+0x32c/0x410 drivers/gpu/drm/drm_atomic_helper.c:1823 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Allocated by task 14732: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:599 [inline] drm_atomic_helper_crtc_duplicate_state+0x6c/0xc0 drivers/gpu/drm/drm_atomic_state_helper.c:177 drm_simple_kms_crtc_duplicate_state+0x86/0xb0 drivers/gpu/drm/drm_simple_kms_helper.c:166 drm_atomic_get_crtc_state+0x15b/0x430 drivers/gpu/drm/drm_atomic.c:362 page_flip_common+0x57/0x310 drivers/gpu/drm/drm_atomic_helper.c:3589 drm_atomic_helper_page_flip+0xb6/0x190 drivers/gpu/drm/drm_atomic_helper.c:3650 drm_mode_page_flip_ioctl+0xf83/0x12c0 drivers/gpu/drm/drm_plane.c:1373 drm_ioctl_kernel+0x280/0x4c0 drivers/gpu/drm/drm_ioctl.c:789 drm_ioctl+0x5cb/0xbf0 drivers/gpu/drm/drm_ioctl.c:892 drm_compat_ioctl+0x322/0x460 drivers/gpu/drm/drm_ioc32.c:988 __do_compat_sys_ioctl+0x2bf/0x330 fs/ioctl.c:972 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 14729: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 drm_simple_kms_crtc_destroy_state+0x8f/0xb0 drivers/gpu/drm/drm_simple_kms_helper.c:177 drm_atomic_state_default_clear+0x3a7/0xde0 drivers/gpu/drm/drm_atomic.c:225 drm_atomic_state_clear drivers/gpu/drm/drm_atomic.c:294 [inline] __drm_atomic_state_free+0x17f/0x2b0 drivers/gpu/drm/drm_atomic.c:311 kref_put include/linux/kref.h:65 [inline] drm_atomic_state_put include/drm/drm_atomic.h:490 [inline] drm_client_modeset_commit_atomic+0x6d5/0x810 drivers/gpu/drm/drm_client_modeset.c:1057 drm_client_modeset_commit_locked+0x14d/0x570 drivers/gpu/drm/drm_client_modeset.c:1154 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1180 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:251 [inline] __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:230 [inline] drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:278 [inline] drm_fb_helper_lastclose+0xc7/0x160 drivers/gpu/drm/drm_fb_helper.c:2005 drm_fbdev_generic_client_restore+0x2c/0x40 drivers/gpu/drm/drm_fbdev_generic.c:258 drm_client_dev_restore+0x188/0x290 drivers/gpu/drm/drm_client.c:257 drm_release+0x40e/0x4f0 drivers/gpu/drm/drm_file.c:497 __fput+0x3f7/0xa70 fs/file_table.c:384 __fput_sync+0x47/0x50 fs/file_table.c:465 __do_sys_close fs/open.c:1572 [inline] __se_sys_close fs/open.c:1557 [inline] __ia32_sys_close+0x87/0xf0 fs/open.c:1557 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 The buggy address belongs to the object at ffff888023d92c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 9 bytes inside of freed 512-byte region [ffff888023d92c00, ffff888023d92e00) The buggy address belongs to the physical page: page:ffffea00008f6400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888023d92800 pfn:0x23d90 head:ffffea00008f6400 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012c42c80 ffffea0000874200 0000000000000003 raw: ffff888023d92800 000000008010000f 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 14400, tgid 14399 (syz-executor.0), ts 1445849892711, free_ts 1445521863826 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426 __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_slab_page mm/slub.c:1872 [inline] allocate_slab+0xa1/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8c7/0x1580 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x340 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1022 [inline] __kmalloc_node+0x52/0x110 mm/slab_common.c:1030 kmalloc_array_node include/linux/slab.h:697 [inline] kcalloc_node include/linux/slab.h:702 [inline] memcg_alloc_slab_cgroups+0xa9/0x170 mm/memcontrol.c:2895 account_slab mm/slab.h:636 [inline] allocate_slab+0x2cb/0x380 mm/slub.c:2035 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8c7/0x1580 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x340 mm/slub.c:3517 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:1099 [inline] kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1242 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:5089 [inline] kvm_dev_ioctl+0x1543/0x1c20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5131 __do_compat_sys_ioctl+0x2bf/0x330 fs/ioctl.c:972 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1136 [inline] free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2405 __unfreeze_partials+0x21d/0x240 mm/slub.c:2655 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:762 [inline] slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x16c/0x3b0 mm/slub.c:3502 getname_flags.part.0+0x50/0x4d0 fs/namei.c:140 getname_flags+0x9c/0xf0 include/linux/audit.h:321 user_path_at_empty+0x2c/0x60 fs/namei.c:2909 user_path_at include/linux/namei.h:57 [inline] __do_sys_chdir fs/open.c:551 [inline] __se_sys_chdir fs/open.c:545 [inline] __ia32_sys_chdir+0xce/0x270 fs/open.c:545 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Memory state around the buggy address: ffff888023d92b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888023d92b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888023d92c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888023d92c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888023d92d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================