================================================================== 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 ffff8881c8a431c0 by task syz-executor.1/26273 CPU: 1 PID: 26273 Comm: syz-executor.1 Not tainted 5.4.197-syzkaller-00015-gf0306959ab7c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18e/0x1d5 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:1387 [inline] tun_free_netdev+0x99/0x3b0 drivers/net/tun.c:2328 netdev_run_todo+0xa3c/0xc80 net/core/dev.c:9445 tun_detach drivers/net/tun.c:751 [inline] tun_chr_close+0xc0/0xd0 drivers/net/tun.c:3523 __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: 0033:0x7fd61806eebb Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007ffe70978570 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007fd61806eebb RDX: 00007fd6181d6d58 RSI: ffffffffffffffff RDI: 0000000000000005 RBP: 00007fd6181d0980 R08: 0000000000000000 R09: 00007fd6181d6d60 R10: 00007ffe70978670 R11: 0000000000000293 R12: 00000000002529db R13: 00007ffe70978670 R14: 00007fd6181cef80 R15: 0000000000000032 The buggy address belongs to the page: page:ffffea00072290c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea0007229088 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 0x152dc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__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+0x2ab/0x6f0 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_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] bpf_map_area_alloc+0x47/0x90 kernel/bpf/syscall.c:149 prealloc_init kernel/bpf/hashtab.c:142 [inline] htab_map_alloc+0x79a/0x11f0 kernel/bpf/hashtab.c:378 find_and_alloc_map kernel/bpf/syscall.c:122 [inline] map_create kernel/bpf/syscall.c:573 [inline] __do_sys_bpf kernel/bpf/syscall.c:2871 [inline] __se_sys_bpf+0x2fe1/0xb990 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+0x7ee/0x920 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4919 [inline] __free_pages+0x45/0x1e0 mm/page_alloc.c:4925 kfree+0x1ef/0x260 mm/slub.c:4068 htab_free_elems kernel/bpf/hashtab.c:116 [inline] prealloc_destroy kernel/bpf/hashtab.c:194 [inline] htab_map_free+0x5a2/0x6f0 kernel/bpf/hashtab.c:1231 bpf_map_free_deferred+0xa6/0x100 kernel/bpf/syscall.c:311 process_one_work+0x6ca/0xc40 kernel/workqueue.c:2287 worker_thread+0xae0/0x1440 kernel/workqueue.c:2433 kthread+0x2d8/0x360 kernel/kthread.c:288 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 Memory state around the buggy address: ffff8881c8a43080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881c8a43100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881c8a43180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881c8a43200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881c8a43280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================