l2tp_core: tunl 3: sockfd_lookup(fd=3) returned -9 l2tp_core: tunl 3: sockfd_lookup(fd=3) returned -9 l2tp_core: tunl 3: sockfd_lookup(fd=3) returned -9 l2tp_core: tunl 3: sockfd_lookup(fd=3) returned -9 ================================================================== BUG: KASAN: use-after-free in inet_shutdown+0x2d3/0x350 net/ipv4/af_inet.c:816 Read of size 4 at addr ffff88809a0da080 by task syz-executor.1/9911 CPU: 1 PID: 9911 Comm: syz-executor.1 Not tainted 4.14.141 #37 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x197 lib/dump_stack.c:53 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 inet_shutdown+0x2d3/0x350 net/ipv4/af_inet.c:816 pppol2tp_session_close+0xa0/0xe0 net/l2tp/l2tp_ppp.c:441 l2tp_tunnel_closeall+0x243/0x380 net/l2tp/l2tp_core.c:1340 l2tp_udp_encap_destroy+0x99/0x100 net/l2tp/l2tp_core.c:1366 udpv6_destroy_sock+0xb3/0xd0 net/ipv6/udp.c:1444 sk_common_release+0x6b/0x310 net/core/sock.c:2984 udp_lib_close+0x16/0x20 include/net/udp.h:203 inet_release+0xec/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:450 __sock_release+0xce/0x2b0 net/socket.c:602 sock_close+0x1b/0x30 net/socket.c:1139 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459879 RSP: 002b:00007f4da7661c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000459879 RDX: 0000000000000032 RSI: 0000000020000080 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4da76626d4 R13: 00000000004bfdeb R14: 00000000004d1c48 R15: 00000000ffffffff Allocated by task 9911: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc+0x12e/0x780 mm/slab.c:3552 sock_alloc_inode+0x1d/0x260 net/socket.c:251 alloc_inode+0x64/0x180 fs/inode.c:209 new_inode_pseudo+0x19/0xf0 fs/inode.c:891 sock_alloc+0x41/0x280 net/socket.c:569 __sock_create+0x8f/0x620 net/socket.c:1239 sock_create net/socket.c:1315 [inline] SYSC_socket net/socket.c:1345 [inline] SyS_socket+0xd3/0x170 net/socket.c:1325 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 9904: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kmem_cache_free+0x83/0x2b0 mm/slab.c:3758 sock_destroy_inode+0x54/0x60 net/socket.c:281 destroy_inode+0xc2/0x120 fs/inode.c:266 evict+0x3e6/0x630 fs/inode.c:571 iput_final fs/inode.c:1516 [inline] iput fs/inode.c:1543 [inline] iput+0x471/0x900 fs/inode.c:1528 dentry_unlink_inode+0x286/0x340 fs/dcache.c:387 __dentry_kill+0x32e/0x580 fs/dcache.c:591 dentry_kill fs/dcache.c:632 [inline] dput.part.0+0x59f/0x750 fs/dcache.c:847 dput+0x20/0x30 fs/dcache.c:811 __fput+0x45f/0x7a0 fs/file_table.c:228 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff88809a0da080 which belongs to the cache sock_inode_cache of size 992 The buggy address is located 0 bytes inside of 992-byte region [ffff88809a0da080, ffff88809a0da460) The buggy address belongs to the page: page:ffffea0002683680 count:1 mapcount:0 mapping:ffff88809a0da080 index:0xffff88809a0daffd flags: 0x1fffc0000000100(slab) raw: 01fffc0000000100 ffff88809a0da080 ffff88809a0daffd 0000000100000003 raw: ffffea0002685560 ffffea0002685460 ffff8880a9e82c00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809a0d9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809a0da000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88809a0da080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809a0da100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809a0da180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================