================================================================== BUG: KASAN: use-after-free in inet_shutdown+0x2c0/0x340 net/ipv4/af_inet.c:816 Read of size 4 at addr ffff888094005180 by task syz-executor.3/7556 CPU: 1 PID: 7556 Comm: syz-executor.3 Not tainted 4.14.173-syzkaller #0 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+0x13e/0x194 lib/dump_stack.c:58 print_address_description.cold+0x7c/0x1e2 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+0xa9/0x2ae mm/kasan/report.c:393 inet_shutdown+0x2c0/0x340 net/ipv4/af_inet.c:816 pppol2tp_session_close+0x99/0xd0 net/l2tp/l2tp_ppp.c:441 l2tp_tunnel_closeall+0x234/0x370 net/l2tp/l2tp_core.c:1345 l2tp_udp_encap_destroy+0x8d/0xf0 net/l2tp/l2tp_core.c:1371 udpv6_destroy_sock+0xa6/0xd0 net/ipv6/udp.c:1444 sk_common_release+0x64/0x2f0 net/core/sock.c:2989 inet_release+0xdf/0x1b0 net/ipv4/af_inet.c:425 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:450 __sock_release+0xcd/0x2b0 net/socket.c:602 sock_close+0x15/0x20 net/socket.c:1139 __fput+0x25f/0x790 fs/file_table.c:210 task_work_run+0x113/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1d6/0x220 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+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4163e1 RSP: 002b:00007ffc588bd700 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00000000004163e1 RDX: 0000000000000000 RSI: ffffffff863d23cb RDI: 0000000000000006 RBP: 0000000000000001 R08: ffffffff8129b8bc R09: 0000000040e793a3 R10: 00007ffc588bd7e0 R11: 0000000000000293 R12: 000000000076c900 R13: 000000000076c900 R14: 000000000010f11a R15: 000000000076c0ec Allocated by task 7558: save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 kmem_cache_alloc+0x127/0x770 mm/slab.c:3552 sock_alloc_inode+0x19/0x250 net/socket.c:251 alloc_inode+0x5d/0x170 fs/inode.c:209 new_inode_pseudo+0x14/0xe0 fs/inode.c:898 sock_alloc+0x3c/0x270 net/socket.c:569 __sock_create+0x89/0x620 net/socket.c:1239 sock_create net/socket.c:1315 [inline] SYSC_socket net/socket.c:1345 [inline] SyS_socket+0xd2/0x170 net/socket.c:1325 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 7566: save_stack+0x32/0xa0 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+0x7c/0x2b0 mm/slab.c:3758 destroy_inode+0xb9/0x110 fs/inode.c:266 iput_final fs/inode.c:1523 [inline] iput fs/inode.c:1550 [inline] iput+0x457/0x8d0 fs/inode.c:1535 dentry_unlink_inode+0x26e/0x330 fs/dcache.c:387 __dentry_kill+0x320/0x550 fs/dcache.c:591 dentry_kill fs/dcache.c:632 [inline] dput.part.0+0x578/0x710 fs/dcache.c:847 dput+0x1b/0x30 fs/dcache.c:811 __fput+0x445/0x790 fs/file_table.c:228 task_work_run+0x113/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1d6/0x220 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+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff888094005180 which belongs to the cache sock_inode_cache of size 992 The buggy address is located 0 bytes inside of 992-byte region [ffff888094005180, ffff888094005560) The buggy address belongs to the page: page:ffffea0002500140 count:1 mapcount:0 mapping:ffff888094005180 index:0xffff888094005ffd flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff888094005180 ffff888094005ffd 0000000100000002 raw: ffffea0000f6b9e0 ffffea000214aae0 ffff8880a9984900 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888094005080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888094005100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888094005180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888094005200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888094005280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================