IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready hrtimer: interrupt took 11237 ns l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 ================================================================== BUG: KASAN: use-after-free in inet_shutdown+0x2dc/0x360 net/ipv4/af_inet.c:824 Read of size 4 at addr ffff8801bf269540 by task syz-executor0/4312 CPU: 0 PID: 4312 Comm: syz-executor0 Not tainted 4.9.123-g8dd3fc2 #79 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d9827b90 ffffffff81eb9689 ffffea0006fc9a00 ffff8801bf269540 0000000000000000 ffff8801bf269540 ffff8801d4eb0058 ffff8801d9827bc8 ffffffff8156c3fe ffff8801bf269540 0000000000000004 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 [] inet_shutdown+0x2dc/0x360 net/ipv4/af_inet.c:824 [] pppol2tp_session_close+0xa0/0xe0 net/l2tp/l2tp_ppp.c:441 [] l2tp_tunnel_closeall+0x231/0x350 net/l2tp/l2tp_core.c:1368 [] l2tp_udp_encap_destroy+0x87/0xe0 net/l2tp/l2tp_core.c:1394 [] udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1336 [] sk_common_release+0x6d/0x300 net/core/sock.c:2727 [] udp_lib_close+0x15/0x20 include/net/udp.h:203 [] inet_release+0xff/0x1d0 net/ipv4/af_inet.c:434 [] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:440 [] sock_release+0x96/0x1c0 net/socket.c:600 [] sock_close+0x16/0x20 net/socket.c:1047 [] __fput+0x263/0x700 fs/file_table.c:208 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x10c/0x180 kernel/task_work.c:116 [] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [] exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:161 [] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline] [] syscall_return_slowpath arch/x86/entry/common.c:260 [inline] [] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Allocated by task 4313: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:609 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547 slab_post_alloc_hook mm/slab.h:417 [inline] slab_alloc_node mm/slub.c:2715 [inline] slab_alloc mm/slub.c:2723 [inline] kmem_cache_alloc+0xbe/0x290 mm/slub.c:2728 sock_alloc_inode+0x1d/0x260 net/socket.c:251 alloc_inode+0x63/0x180 fs/inode.c:207 new_inode_pseudo+0x17/0xe0 fs/inode.c:890 sock_alloc+0x41/0x280 net/socket.c:568 __sock_create+0x8d/0x5f0 net/socket.c:1147 sock_create net/socket.c:1223 [inline] SYSC_socket net/socket.c:1253 [inline] SyS_socket+0xf0/0x1b0 net/socket.c:1233 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb Freed by task 4310: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kmem_cache_free+0xbe/0x310 mm/slub.c:2980 sock_destroy_inode+0x56/0x70 net/socket.c:281 destroy_inode+0xc5/0x120 fs/inode.c:264 evict+0x32b/0x4f0 fs/inode.c:570 iput_final fs/inode.c:1516 [inline] iput+0x371/0x900 fs/inode.c:1543 dentry_unlink_inode+0x277/0x330 fs/dcache.c:367 __dentry_kill+0x280/0x4c0 fs/dcache.c:569 dentry_kill fs/dcache.c:610 [inline] dput.part.29+0x5cf/0x7b0 fs/dcache.c:827 dput+0x1f/0x30 fs/dcache.c:789 __fput+0x42f/0x700 fs/file_table.c:226 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x10c/0x180 kernel/task_work.c:116 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline] syscall_return_slowpath arch/x86/entry/common.c:260 [inline] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_swapgs+0x5d/0xdb The buggy address belongs to the object at ffff8801bf269540 which belongs to the cache sock_inode_cache of size 960 The buggy address is located 0 bytes inside of 960-byte region [ffff8801bf269540, ffff8801bf269900) The buggy address belongs to the page: page:ffffea0006fc9a00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x8000000000004080(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801bf269400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801bf269480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801bf269500: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801bf269580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801bf269600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================