================================================================== BUG: KASAN: slab-use-after-free in drm_atomic_helper_wait_for_vblanks.part.0+0x84f/0x930 drivers/gpu/drm/drm_atomic_helper.c:1661 Read of size 1 at addr ffff88802378cc09 by task kworker/u16:1/13 CPU: 2 PID: 13 Comm: kworker/u16:1 Not tainted 6.8.0-rc6-syzkaller-g45ec2f5f6ed3 #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:377 [inline] print_report+0xc4/0x620 mm/kasan/report.c:488 kasan_report+0xda/0x110 mm/kasan/report.c:601 drm_atomic_helper_wait_for_vblanks.part.0+0x84f/0x930 drivers/gpu/drm/drm_atomic_helper.c:1661 drm_atomic_helper_wait_for_vblanks drivers/gpu/drm/drm_atomic_helper.c:1657 [inline] drm_atomic_helper_commit_tail+0xcb/0xf0 drivers/gpu/drm/drm_atomic_helper.c:1757 commit_tail+0x356/0x410 drivers/gpu/drm/drm_atomic_helper.c:1834 process_one_work+0x889/0x15e0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x12a0 kernel/workqueue.c:2787 kthread+0x2c6/0x3b0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243 Allocated by task 5721: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:372 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:389 kmalloc include/linux/slab.h:590 [inline] drm_atomic_helper_crtc_duplicate_state+0x70/0xd0 drivers/gpu/drm/drm_atomic_state_helper.c:177 drm_atomic_get_crtc_state+0x162/0x440 drivers/gpu/drm/drm_atomic.c:362 page_flip_common+0x57/0x320 drivers/gpu/drm/drm_atomic_helper.c:3629 drm_atomic_helper_page_flip+0xb6/0x190 drivers/gpu/drm/drm_atomic_helper.c:3690 drm_mode_page_flip_ioctl+0x103f/0x1470 drivers/gpu/drm/drm_plane.c:1489 drm_ioctl_kernel+0x1ec/0x3e0 drivers/gpu/drm/drm_ioctl.c:744 drm_ioctl+0x5d8/0xc00 drivers/gpu/drm/drm_ioctl.c:841 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x270 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 Freed by task 5720: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:643 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x121/0x1c0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kfree+0x124/0x370 mm/slub.c:4409 drm_atomic_state_default_clear+0x3aa/0xde0 drivers/gpu/drm/drm_atomic.c:225 drm_atomic_state_clear drivers/gpu/drm/drm_atomic.c:294 [inline] __drm_atomic_state_free+0x185/0x2b0 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+0x6db/0x810 drivers/gpu/drm/drm_client_modeset.c:1057 drm_client_modeset_commit_locked+0x14d/0x580 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+0x188/0x2a0 drivers/gpu/drm/drm_client.c:247 drm_release+0x32f/0x3e0 drivers/gpu/drm/drm_file.c:437 __fput+0x270/0xb80 fs/file_table.c:376 __fput_sync+0x47/0x50 fs/file_table.c:461 __do_sys_close fs/open.c:1554 [inline] __se_sys_close fs/open.c:1539 [inline] __x64_sys_close+0x87/0x100 fs/open.c:1539 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x270 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 The buggy address belongs to the object at ffff88802378cc00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 9 bytes inside of freed 512-byte region [ffff88802378cc00, ffff88802378ce00) The buggy address belongs to the physical page: page:ffffea00008de300 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2378c head:ffffea00008de300 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888014c42c80 ffffea0000a77a00 dead000000000002 raw: 0000000000000000 0000000000100010 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 4665, tgid 4665 (udevd), ts 78790336769, free_ts 73008917105 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3311 __alloc_pages+0x22f/0x2440 mm/page_alloc.c:4567 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2190 [inline] allocate_slab mm/slub.c:2354 [inline] new_slab+0xcc/0x3a0 mm/slub.c:2407 ___slab_alloc+0x4af/0x19a0 mm/slub.c:3540 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3625 __slab_alloc_node mm/slub.c:3678 [inline] slab_alloc_node mm/slub.c:3850 [inline] kmalloc_trace+0x30b/0x340 mm/slub.c:4007 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:711 [inline] kernfs_fop_open+0x28b/0xd40 fs/kernfs/file.c:621 do_dentry_open+0x8da/0x18c0 fs/open.c:953 do_open fs/namei.c:3645 [inline] path_openat+0x1e00/0x29a0 fs/namei.c:3802 do_filp_open+0x1de/0x440 fs/namei.c:3829 do_sys_openat2+0x17a/0x1e0 fs/open.c:1404 do_sys_open fs/open.c:1419 [inline] __do_sys_openat fs/open.c:1435 [inline] __se_sys_openat fs/open.c:1430 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1430 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x270 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 page last free pid 5331 tgid 5331 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2346 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2486 __folio_put_small mm/swap.c:106 [inline] __folio_put+0xc3/0x110 mm/swap.c:129 folio_put include/linux/mm.h:1494 [inline] put_page include/linux/mm.h:1563 [inline] anon_pipe_buf_release+0x3fa/0x4b0 fs/pipe.c:138 pipe_buf_release include/linux/pipe_fs_i.h:219 [inline] pipe_update_tail fs/pipe.c:234 [inline] pipe_read+0x64a/0x1410 fs/pipe.c:354 call_read_iter include/linux/fs.h:2081 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0xa01/0xb80 fs/read_write.c:476 ksys_read+0x1f8/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x270 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 Memory state around the buggy address: ffff88802378cb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802378cb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802378cc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802378cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802378cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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