================================================================== BUG: KASAN: use-after-free in notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 Read of size 8 at addr ffff8880741e9f98 by task syz-executor.2/8305 CPU: 0 PID: 8305 Comm: syz-executor.2 Not tainted 6.1.0-rc4-syzkaller-01127-gb4b221bd79a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 call_netdevice_notifiers_info+0x86/0x130 net/core/dev.c:1941 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline] call_netdevice_notifiers net/core/dev.c:1996 [inline] netdev_wait_allrefs_any net/core/dev.c:10227 [inline] netdev_run_todo+0xbc6/0x1100 net/core/dev.c:10341 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xe4/0x190 drivers/net/tun.c:3460 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb3d/0x2a30 kernel/exit.c:820 do_group_exit+0xd4/0x2a0 kernel/exit.c:950 get_signal+0x21b1/0x2440 kernel/signal.c:2858 arch_do_signal_or_restart+0x86/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa9a1e8b639 Code: Unable to access opcode bytes at 0x7fa9a1e8b60f. RSP: 002b:00007fa9a2cc6218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fa9a1fabf88 RCX: 00007fa9a1e8b639 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa9a1fabf88 RBP: 00007fa9a1fabf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa9a1fabf8c R13: 00007ffc52951cbf R14: 00007fa9a2cc6300 R15: 0000000000022000 Allocated by task 3668: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x82/0x90 mm/kasan/common.c:325 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x2b4/0x3d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:679 [inline] net_alloc net/core/net_namespace.c:411 [inline] copy_net_ns+0x12b/0x6b0 net/core/net_namespace.c:470 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc5/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x449/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 7888: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free+0xee/0x5c0 mm/slub.c:3683 net_free net/core/net_namespace.c:444 [inline] net_free net/core/net_namespace.c:436 [inline] cleanup_net+0x8ca/0xb10 net/core/net_namespace.c:627 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x693/0x13b0 kernel/workqueue.c:1517 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xaf0 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0x156/0x1d0 kernel/time/timer.c:1805 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x693/0x13b0 kernel/workqueue.c:1517 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xaf0 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0x156/0x1d0 kernel/time/timer.c:1805 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 The buggy address belongs to the object at ffff8880741e9cc0 which belongs to the cache net_namespace of size 7104 The buggy address is located 728 bytes inside of 7104-byte region [ffff8880741e9cc0, ffff8880741eb880) The buggy address belongs to the physical page: page:ffffea0001d07a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880741ed640 pfn:0x741e8 head:ffffea0001d07a00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88807b69b9c1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001fab408 ffff8880121e3348 ffff8880121e2500 raw: ffff8880741ed640 0000000000040003 00000001ffffffff ffff88807b69b9c1 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3663, tgid 3663 (syz-executor.0), ts 123394023048, free_ts 123362513104 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4288 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5555 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x31a/0x3d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:679 [inline] net_alloc net/core/net_namespace.c:411 [inline] copy_net_ns+0x12b/0x6b0 net/core/net_namespace.c:470 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc5/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x449/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x1d/0x4d0 mm/page_alloc.c:3483 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2586 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x184/0x210 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x2b4/0x3d0 mm/slub.c:3422 vm_area_dup+0x85/0x380 kernel/fork.c:466 dup_mmap+0x655/0x10b0 kernel/fork.c:640 dup_mm+0x91/0x370 kernel/fork.c:1526 copy_mm kernel/fork.c:1575 [inline] copy_process+0x3bc6/0x7190 kernel/fork.c:2253 kernel_clone+0xeb/0x980 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2812 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff8880741e9e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880741e9f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880741e9f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880741ea000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880741ea080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================