================================================================== BUG: KASAN: use-after-free in inet_shutdown+0x2d4/0x350 net/ipv4/af_inet.c:817 Read of size 4 at addr ffff8801d1bef1c0 by task syz-executor1/6378 CPU: 1 PID: 6378 Comm: syz-executor1 Not tainted 4.15.0-rc9+ #275 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+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 inet_shutdown+0x2d4/0x350 net/ipv4/af_inet.c:817 pppol2tp_session_close+0x92/0xf0 net/l2tp/l2tp_ppp.c:430 l2tp_tunnel_closeall+0x305/0x410 net/l2tp/l2tp_core.c:1294 l2tp_udp_encap_destroy+0x95/0x100 net/l2tp/l2tp_core.c:1317 udpv6_destroy_sock+0x161/0x190 net/ipv6/udp.c:1437 sk_common_release+0x6b/0x2f0 net/core/sock.c:2989 udp_lib_close+0x15/0x20 include/net/udp.h:203 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:426 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432 sock_release+0x8d/0x1e0 net/socket.c:602 sock_close+0x16/0x20 net/socket.c:1131 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 RIP: 0033:0x452ef9 RSP: 002b:00007f847bd38c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000071bea0 RCX: 0000000000452ef9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013 RBP: 0000000000000052 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ef850 R13: 00000000ffffffff R14: 00007f847bd396d4 R15: 0000000000000000 Allocated by task 6381: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544 sock_alloc_inode+0x70/0x300 net/socket.c:250 alloc_inode+0x65/0x180 fs/inode.c:208 new_inode_pseudo+0x69/0x190 fs/inode.c:890 sock_alloc+0x41/0x270 net/socket.c:571 __sock_create+0x148/0x850 net/socket.c:1231 sock_create net/socket.c:1307 [inline] SYSC_socket net/socket.c:1337 [inline] SyS_socket+0xeb/0x1d0 net/socket.c:1317 entry_SYSCALL_64_fastpath+0x29/0xa0 Freed by task 6381: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3488 [inline] kmem_cache_free+0x83/0x2a0 mm/slab.c:3746 sock_destroy_inode+0x56/0x70 net/socket.c:280 destroy_inode+0x15d/0x200 fs/inode.c:265 evict+0x57e/0x920 fs/inode.c:570 iput_final fs/inode.c:1515 [inline] iput+0x7b9/0xaf0 fs/inode.c:1542 dentry_unlink_inode+0x4b0/0x5e0 fs/dcache.c:375 __dentry_kill+0x3b7/0x6d0 fs/dcache.c:572 dentry_kill fs/dcache.c:613 [inline] dput.part.23+0x6fb/0x830 fs/dcache.c:823 dput+0x1f/0x30 fs/dcache.c:787 __fput+0x51c/0x7e0 fs/file_table.c:228 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 The buggy address belongs to the object at ffff8801d1bef1c0 which belongs to the cache sock_inode_cache of size 992 The buggy address is located 0 bytes inside of 992-byte region [ffff8801d1bef1c0, ffff8801d1bef5a0) The buggy address belongs to the page: page:ffffea000746fbc0 count:1 mapcount:0 mapping:ffff8801d1bef1c0 index:0xffff8801d1befffd flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d1bef1c0 ffff8801d1befffd 0000000100000003 raw: ffffea0006e959e0 ffffea000746fc60 ffff8801d986f9c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d1bef080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d1bef100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801d1bef180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801d1bef200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d1bef280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================