================================================================== 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 ffff88802a5f2409 by task kworker/u16:9/1096 CPU: 0 PID: 1096 Comm: kworker/u16:9 Not tainted 6.8.0-rc4-syzkaller-g7e90b5c295ec-dirty #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:242 Allocated by task 5653: 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 5652: 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:640 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+0x70f/0x850 drivers/gpu/drm/drm_client_modeset.c:1057 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1156 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1182 __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 ffff88802a5f2400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 9 bytes inside of freed 512-byte region [ffff88802a5f2400, ffff88802a5f2600) The buggy address belongs to the physical page: page:ffffea0000a97c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802a5f3c00 pfn:0x2a5f0 head:ffffea0000a97c00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000a40(workingset|slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000a40 ffff888014c42c80 ffffea0000a4e410 ffffea00009bd610 raw: ffff88802a5f3c00 000000000010000b 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5166, tgid 5166 (syz-executor.0), ts 45262333507, free_ts 42769982140 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] __do_kmalloc_node mm/slub.c:3980 [inline] __kmalloc+0x3b8/0x440 mm/slub.c:3994 kmalloc include/linux/slab.h:594 [inline] kzalloc include/linux/slab.h:711 [inline] fib6_info_alloc+0x40/0x100 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x337/0x1b70 net/ipv6/route.c:3749 ip6_route_add+0x26/0x150 net/ipv6/route.c:3843 addrconf_prefix_route+0x2fe/0x510 net/ipv6/addrconf.c:2437 inet6_addr_add+0x609/0xbe0 net/ipv6/addrconf.c:3004 inet6_rtm_newaddr+0x11de/0x1ab0 net/ipv6/addrconf.c:4976 rtnetlink_rcv_msg+0x3c7/0xe10 net/core/rtnetlink.c:6615 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x542/0x820 net/netlink/af_netlink.c:1367 page last free pid 5115 tgid 5115 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 qlink_free mm/kasan/quarantine.c:160 [inline] qlist_free_all+0x58/0x150 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:324 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] kmem_cache_alloc_bulk+0x439/0x950 mm/slub.c:4655 mt_alloc_bulk lib/maple_tree.c:167 [inline] mas_alloc_nodes+0x39b/0x860 lib/maple_tree.c:1264 mas_node_count_gfp+0x105/0x130 lib/maple_tree.c:1322 mas_preallocate+0x3bb/0x1020 lib/maple_tree.c:5508 vma_iter_prealloc mm/internal.h:1147 [inline] __split_vma+0x47a/0x1190 mm/mmap.c:2348 split_vma mm/mmap.c:2407 [inline] vma_modify+0x32a/0x460 mm/mmap.c:2449 vma_modify_flags include/linux/mm.h:3283 [inline] mprotect_fixup+0x228/0xc90 mm/mprotect.c:635 do_mprotect_pkey+0x860/0xd70 mm/mprotect.c:809 __do_sys_mprotect mm/mprotect.c:830 [inline] __se_sys_mprotect mm/mprotect.c:827 [inline] __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:827 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: ffff88802a5f2300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802a5f2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802a5f2400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802a5f2480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802a5f2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================