================================================================== BUG: KASAN: use-after-free in __write_once_size include/linux/compiler.h:295 [inline] BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:789 [inline] BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline] BUG: KASAN: use-after-free in detach_if_pending+0x160/0x360 kernel/time/timer.c:841 Write of size 8 at addr ffff8881e084b1c0 by task syz.2.234/1203 CPU: 0 PID: 1203 Comm: syz.2.234 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x241 lib/dump_stack.c:118 print_address_description+0x8c/0x600 mm/kasan/report.c:384 __kasan_report+0xf3/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 __write_once_size include/linux/compiler.h:295 [inline] __hlist_del include/linux/list.h:789 [inline] detach_timer kernel/time/timer.c:824 [inline] detach_if_pending+0x160/0x360 kernel/time/timer.c:841 try_to_del_timer_sync kernel/time/timer.c:1267 [inline] del_timer_sync+0x13c/0x230 kernel/time/timer.c:1410 tun_flow_uninit+0x2c/0x280 drivers/net/tun.c:1452 tun_free_netdev+0x77/0x190 drivers/net/tun.c:2404 netdev_run_todo+0xb7f/0xdf0 net/core/dev.c:9477 tun_detach drivers/net/tun.c:766 [inline] tun_chr_close+0xc1/0x130 drivers/net/tun.c:3563 __fput+0x262/0x680 fs/file_table.c:281 task_work_run+0x140/0x170 kernel/task_work.c:113 get_signal+0x13c6/0x1440 kernel/signal.c:2532 do_signal+0xb0/0x11f0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xc0/0x1a0 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f13cdc78169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f13cc29ffe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f13cde91160 RCX: 00007f13cdc78169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000042000000 RBP: 00007f13cdcf92a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f13cde91160 R15: 00007fff6eb981e8 The buggy address belongs to the page: page:ffffea00078212c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea0007821288 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 2, migratetype Unmovable, gfp_mask 0x102800(GFP_NOWAIT|__GFP_NOWARN|__GFP_HARDWALL) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x18f/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893 __alloc_pages include/linux/gfp.h:503 [inline] __alloc_pages_node include/linux/gfp.h:516 [inline] alloc_pages_node include/linux/gfp.h:530 [inline] stack_depot_save+0x35a/0x480 lib/stackdepot.c:267 save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x21c/0x270 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook mm/slub.c:1494 [inline] slab_free mm/slub.c:3080 [inline] kfree+0x123/0x370 mm/slub.c:4071 kobject_uevent_env+0x33e/0x710 lib/kobject_uevent.c:640 device_del+0xe8a/0xfa0 drivers/base/core.c:3098 rollback_registered_many+0xed6/0x1330 net/core/dev.c:8674 unregister_netdevice_many+0x46/0x250 net/core/dev.c:9805 ip_tunnel_delete_nets+0x33b/0x380 net/ipv4/ip_tunnel.c:1129 ops_exit_list net/core/net_namespace.c:187 [inline] setup_net+0x639/0x990 net/core/net_namespace.c:371 copy_net_ns+0x30d/0x510 net/core/net_namespace.c:489 create_new_namespaces+0x47a/0x570 kernel/nsproxy.c:103 copy_namespaces+0x169/0x1b0 kernel/nsproxy.c:161 copy_process+0x12da/0x3230 kernel/fork.c:2055 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1176 [inline] __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4955 [inline] __free_pages mm/page_alloc.c:4961 [inline] free_pages+0xf6/0x1b0 mm/page_alloc.c:4969 stack_depot_save+0x42b/0x480 lib/stackdepot.c:300 save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x21c/0x270 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook mm/slub.c:1494 [inline] slab_free mm/slub.c:3080 [inline] kfree+0x123/0x370 mm/slub.c:4071 kobject_uevent_env+0x33e/0x710 lib/kobject_uevent.c:640 device_del+0xe8a/0xfa0 drivers/base/core.c:3098 rollback_registered_many+0xed6/0x1330 net/core/dev.c:8674 unregister_netdevice_many+0x46/0x250 net/core/dev.c:9805 ip_tunnel_delete_nets+0x33b/0x380 net/ipv4/ip_tunnel.c:1129 ops_exit_list net/core/net_namespace.c:187 [inline] setup_net+0x639/0x990 net/core/net_namespace.c:371 copy_net_ns+0x30d/0x510 net/core/net_namespace.c:489 create_new_namespaces+0x47a/0x570 kernel/nsproxy.c:103 copy_namespaces+0x169/0x1b0 kernel/nsproxy.c:161 copy_process+0x12da/0x3230 kernel/fork.c:2055 _do_fork+0x197/0x900 kernel/fork.c:2399 Memory state around the buggy address: ffff8881e084b080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e084b100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881e084b180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881e084b200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e084b280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 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