================================================================== 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:771 [inline] BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline] BUG: KASAN: use-after-free in detach_if_pending kernel/time/timer.c:841 [inline] BUG: KASAN: use-after-free in try_to_del_timer_sync+0x27c/0x460 kernel/time/timer.c:1238 Write of size 8 at addr ffff8881ed5971c0 by task syz-executor.1/2200 CPU: 1 PID: 2200 Comm: syz-executor.1 Not tainted 5.4.210-syzkaller-00003-g5a34019eb955 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x241 lib/dump_stack.c:118 print_address_description+0x8c/0x630 mm/kasan/report.c:384 __kasan_report+0xf6/0x130 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:771 [inline] detach_timer kernel/time/timer.c:824 [inline] detach_if_pending kernel/time/timer.c:841 [inline] try_to_del_timer_sync+0x27c/0x460 kernel/time/timer.c:1238 del_timer_sync+0x74/0xd0 kernel/time/timer.c:1379 tun_flow_uninit drivers/net/tun.c:1398 [inline] tun_free_netdev+0x99/0x3b0 drivers/net/tun.c:2339 netdev_run_todo+0xb41/0xdb0 net/core/dev.c:9445 tun_detach drivers/net/tun.c:760 [inline] tun_chr_close+0xc0/0xd0 drivers/net/tun.c:3534 __fput+0x261/0x680 fs/file_table.c:281 task_work_run+0x186/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x1ba/0x1d0 arch/x86/entry/common.c:163 prepare_exit_to_usermode+0x17c/0x1d0 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f29eb499639 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f29ea20d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007f29eb5b9f80 RCX: 00007f29eb499639 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f29eb4f4ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffed360312f R14: 00007f29ea20d300 R15: 0000000000022000 The buggy address belongs to the page: page:ffffea0007b565c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea0007b56588 0000000000000000 raw: 0000000000000000 00000000000c0000 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 0x140dc0(GFP_USER|__GFP_COMP|__GFP_ZERO) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x194/0x380 mm/page_alloc.c:2171 get_page_from_freelist+0x524/0x560 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x372/0x860 mm/page_alloc.c:4857 __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] kmalloc_order mm/slab_common.c:1342 [inline] kmalloc_order_trace+0x2a/0xf0 mm/slab_common.c:1358 kmalloc_large include/linux/slab.h:485 [inline] kmalloc include/linux/slab.h:549 [inline] kzalloc include/linux/slab.h:690 [inline] bpf_check+0x100/0xb740 kernel/bpf/verifier.c:9534 bpf_prog_load kernel/bpf/syscall.c:1724 [inline] __do_sys_bpf kernel/bpf/syscall.c:2889 [inline] __se_sys_bpf+0x77ec/0xbba0 kernel/bpf/syscall.c:2847 do_syscall_64+0xcb/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 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+0x7fe/0x930 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4919 [inline] __free_pages+0x8f/0x250 mm/page_alloc.c:4925 kfree+0x1ef/0x260 mm/slub.c:4068 bpf_check+0x4b27/0xb740 kernel/bpf/verifier.c:9704 bpf_prog_load kernel/bpf/syscall.c:1724 [inline] __do_sys_bpf kernel/bpf/syscall.c:2889 [inline] __se_sys_bpf+0x77ec/0xbba0 kernel/bpf/syscall.c:2847 do_syscall_64+0xcb/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Memory state around the buggy address: ffff8881ed597080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881ed597100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881ed597180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881ed597200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881ed597280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================