================================================================== BUG: KASAN: slab-use-after-free in drm_atomic_helper_wait_for_vblanks.part.0+0x8c0/0x9b0 drivers/gpu/drm/drm_atomic_helper.c:1700 Read of size 1 at addr ffff888027048009 by task kworker/u32:10/1253 CPU: 1 UID: 0 PID: 1253 Comm: kworker/u32:10 Not tainted 6.16.0-rc5-syzkaller-gd7b8f8e20813 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events_unbound commit_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 drm_atomic_helper_wait_for_vblanks.part.0+0x8c0/0x9b0 drivers/gpu/drm/drm_atomic_helper.c:1700 drm_atomic_helper_wait_for_vblanks drivers/gpu/drm/drm_atomic_helper.c:1696 [inline] drm_atomic_helper_commit_tail+0xcb/0xf0 drivers/gpu/drm/drm_atomic_helper.c:1796 commit_tail+0x35b/0x400 drivers/gpu/drm/drm_atomic_helper.c:1873 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6562: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:905 [inline] drm_atomic_helper_crtc_duplicate_state+0x70/0xd0 drivers/gpu/drm/drm_atomic_state_helper.c:177 drm_atomic_get_crtc_state+0x16e/0x450 drivers/gpu/drm/drm_atomic.c:360 page_flip_common+0x57/0x320 drivers/gpu/drm/drm_atomic_helper.c:3717 drm_atomic_helper_page_flip+0xb6/0x180 drivers/gpu/drm/drm_atomic_helper.c:3778 drm_mode_page_flip_ioctl+0x102c/0x1460 drivers/gpu/drm/drm_plane.c:1542 drm_ioctl_kernel+0x1f4/0x3e0 drivers/gpu/drm/drm_ioctl.c:796 drm_ioctl+0x5c9/0xc30 drivers/gpu/drm/drm_ioctl.c:893 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6561: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 drm_atomic_state_default_clear+0x455/0xe40 drivers/gpu/drm/drm_atomic.c:224 drm_atomic_state_clear drivers/gpu/drm/drm_atomic.c:293 [inline] __drm_atomic_state_free+0x185/0x2b0 drivers/gpu/drm/drm_atomic.c:310 kref_put include/linux/kref.h:65 [inline] drm_atomic_state_put include/drm/drm_atomic.h:588 [inline] drm_client_modeset_commit_atomic+0x6b2/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1107 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1204 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1230 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:237 [inline] __drm_fb_helper_restore_fbdev_mode_unlocked+0x19f/0x200 drivers/gpu/drm/drm_fb_helper.c:216 drm_fbdev_client_restore+0x2c/0x40 drivers/gpu/drm/clients/drm_fbdev_client.c:31 drm_client_dev_restore+0x1f6/0x2a0 drivers/gpu/drm/drm_client_event.c:116 drm_lastclose drivers/gpu/drm/drm_file.c:396 [inline] drm_release+0x2c4/0x360 drivers/gpu/drm/drm_file.c:429 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888027048000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 9 bytes inside of freed 512-byte region [ffff888027048000, ffff888027048200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888027049c00 pfn:0x27048 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b842c80 ffffea0000dca600 dead000000000002 raw: ffff888027049c00 000000008010000d 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842c80 ffffea0000dca600 dead000000000002 head: ffff888027049c00 000000008010000d 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea00009c1201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5364, tgid 5364 (udevd), ts 28904287532, free_ts 28811157507 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] kernfs_fop_open+0x244/0xda0 fs/kernfs/file.c:623 do_dentry_open+0x744/0x1c10 fs/open.c:964 vfs_open+0x82/0x3f0 fs/open.c:1094 do_open fs/namei.c:3896 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4055 do_filp_open+0x20b/0x470 fs/namei.c:4082 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 page last free pid 5368 tgid 5368 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x1d4/0x510 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] tomoyo_realpath_from_path+0xc2/0x6e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x245/0x580 security/tomoyo/file.c:723 tomoyo_path_chown+0x14b/0x1b0 security/tomoyo/tomoyo.c:384 security_path_chown+0x12a/0x2e0 security/security.c:2080 chown_common+0x3d3/0x680 fs/open.c:785 do_fchownat+0x1a7/0x200 fs/open.c:821 __do_sys_chown fs/open.c:841 [inline] __se_sys_chown fs/open.c:839 [inline] __x64_sys_chown+0x7b/0xc0 fs/open.c:839 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888027047f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888027047f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888027048000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888027048080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888027048100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================