================================================================== BUG: KASAN: use-after-free in inet_shutdown+0x2c0/0x340 net/ipv4/af_inet.c:816 Read of size 4 at addr ffff888041349040 by task syz-executor.4/11579 CPU: 1 PID: 11579 Comm: syz-executor.4 Not tainted 4.14.230-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+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load4_noabort+0x68/0x70 mm/kasan/report.c:429 audit: type=1804 audit(1618332160.083:38): pid=11621 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.0" name="/root/syzkaller-testdir995308418/syzkaller.xH34Rt/48/file0/file0" dev="sda1" ino=14112 res=1 inet_shutdown+0x2c0/0x340 net/ipv4/af_inet.c:816 pppol2tp_session_close+0x8f/0xe0 net/l2tp/l2tp_ppp.c:449 l2tp_tunnel_closeall+0x235/0x370 net/l2tp/l2tp_core.c:1347 l2tp_udp_encap_destroy+0x8d/0xf0 net/l2tp/l2tp_core.c:1373 udpv6_destroy_sock+0xef/0x190 net/ipv6/udp.c:1444 sk_common_release+0x64/0x2c0 net/core/sock.c:3015 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/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 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+0x46/0xbb RIP: 0033:0x41926b RSP: 002b:00007ffce78be930 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 000000000041926b RDX: 000000004b8f8d55 RSI: 000000000b86e389 RDI: 0000000000000007 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b2e9243b4 R10: 000cba3d53efd32f R11: 0000000000000293 R12: 000000000056c9e0 R13: 000000000056c9e0 R14: 000000000056bf60 R15: 000000000003abd1 Allocated by task 11580: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552 sock_alloc_inode+0x19/0x250 net/socket.c:251 alloc_inode+0x5d/0x170 fs/inode.c:210 new_inode_pseudo+0x14/0xe0 fs/inode.c:899 sock_alloc+0x3c/0x270 net/socket.c:569 __sock_create+0x8a/0x620 net/socket.c:1239 sock_create net/socket.c:1315 [inline] SYSC_socket net/socket.c:1345 [inline] SyS_socket+0xd1/0x1b0 net/socket.c:1325 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 11580: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 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:267 iput_final fs/inode.c:1524 [inline] iput+0x458/0x7e0 fs/inode.c:1551 dentry_unlink_inode+0x25c/0x310 fs/dcache.c:387 __dentry_kill+0x320/0x550 fs/dcache.c:591 dentry_kill fs/dcache.c:632 [inline] dput.part.0+0x56f/0x710 fs/dcache.c:847 dput+0x1b/0x30 fs/dcache.c:811 __fput+0x445/0x7a0 fs/file_table.c:228 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 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+0x46/0xbb The buggy address belongs to the object at ffff888041349040 which belongs to the cache sock_inode_cache of size 1000 The buggy address is located 0 bytes inside of 1000-byte region [ffff888041349040, ffff888041349428) The buggy address belongs to the page: page:ffffea000104d240 count:1 mapcount:0 mapping:ffff888041349040 index:0xffff888041349ffd flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff888041349040 ffff888041349ffd 0000000100000003 raw: ffffea000104c020 ffffea000104d2a0 ffff88823b3f93c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888041348f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888041348f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888041349000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff888041349080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888041349100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs (loop0): Unrecognized mount option "ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ" or missing value audit: type=1804 audit(1618332160.703:39): pid=11652 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.0" name="/root/syzkaller-testdir995308418/syzkaller.xH34Rt/48/file0/file0" dev="sda1" ino=14112 res=1