================================================================== BUG: KASAN: use-after-free in inet_shutdown+0x2e9/0x370 net/ipv4/af_inet.c:809 Read of size 4 at addr ffff8800b5b48880 by task syz-executor1/7583 CPU: 0 PID: 7583 Comm: syz-executor1 Not tainted 4.4.140-g789274d #67 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 de044a2faf7c19dc ffff8800add07bc0 ffffffff81e0e08d ffffea0002d6d200 ffff8800b5b48880 0000000000000000 ffff8800b5b48880 ffff8801c9da0f58 ffff8800add07bf8 ffffffff81515a56 ffff8800b5b48880 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_address_description+0x6c/0x216 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408 [] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428 [] inet_shutdown+0x2e9/0x370 net/ipv4/af_inet.c:809 [] pppol2tp_session_close+0xa0/0xe0 net/l2tp/l2tp_ppp.c:458 [] l2tp_tunnel_closeall+0x205/0x350 net/l2tp/l2tp_core.c:1274 [] l2tp_udp_encap_destroy+0x8b/0xf0 net/l2tp/l2tp_core.c:1300 [] udp_destroy_sock+0x118/0x1a0 net/ipv4/udp.c:2056 [] sk_common_release+0x6d/0x300 net/core/sock.c:2680 [] udp_lib_close+0x15/0x20 include/net/udp.h:190 [] inet_release+0xff/0x1d0 net/ipv4/af_inet.c:435 [] sock_release+0x96/0x1c0 net/socket.c:586 [] sock_close+0x16/0x20 net/socket.c:1037 [] __fput+0x235/0x6f0 fs/file_table.c:208 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x10f/0x190 kernel/task_work.c:115 [] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:252 [] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline] [] syscall_return_slowpath+0x1b5/0x1f0 arch/x86/entry/common.c:348 [] int_ret_from_sys_call+0x25/0xa3 Allocated by task 7583: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616 [] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554 [] slab_post_alloc_hook mm/slub.c:1349 [inline] [] slab_alloc_node mm/slub.c:2615 [inline] [] slab_alloc mm/slub.c:2623 [inline] [] kmem_cache_alloc+0xbe/0x2a0 mm/slub.c:2628 [] sock_alloc_inode+0x1d/0x260 net/socket.c:250 [] alloc_inode+0x63/0x180 fs/inode.c:198 [] new_inode_pseudo+0x17/0xe0 fs/inode.c:878 [] sock_alloc+0x41/0x280 net/socket.c:555 [] __sock_create+0x8d/0x5f0 net/socket.c:1141 [] sock_create net/socket.c:1217 [inline] [] SYSC_socket net/socket.c:1247 [inline] [] SyS_socket+0xf0/0x1b0 net/socket.c:1227 [] entry_SYSCALL_64_fastpath+0x22/0x9e Freed by task 7565: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kmem_cache_free+0xbe/0x340 mm/slub.c:2881 [] sock_destroy_inode+0x56/0x70 net/socket.c:280 [] destroy_inode+0xc2/0x120 fs/inode.c:255 [] evict+0x322/0x4f0 fs/inode.c:559 [] iput_final fs/inode.c:1477 [inline] [] iput+0x391/0x980 fs/inode.c:1504 [] dentry_iput fs/dcache.c:372 [inline] [] __dentry_kill+0x492/0x5f0 fs/dcache.c:559 [] dentry_kill fs/dcache.c:603 [inline] [] dput.part.26+0x587/0x760 fs/dcache.c:818 [] dput+0x1f/0x30 fs/dcache.c:782 [] __fput+0x401/0x6f0 fs/file_table.c:226 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x10f/0x190 kernel/task_work.c:115 [] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:252 [] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline] [] syscall_return_slowpath+0x1b5/0x1f0 arch/x86/entry/common.c:348 [] int_ret_from_sys_call+0x25/0xa3 The buggy address belongs to the object at ffff8800b5b48880 which belongs to the cache sock_inode_cache of size 936 The buggy address is located 0 bytes inside of 936-byte region [ffff8800b5b48880, ffff8800b5b48c28) The buggy address belongs to the page: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 6 Comm: kworker/u4:0 Not tainted 4.4.140-g789274d #67 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net task: ffff8801d9a08000 task.stack: ffff8801d9a10000 RIP: 0010:[] [] lookup_object lib/debugobjects.c:120 [inline] RIP: 0010:[] [] debug_object_deactivate+0x191/0x340 lib/debugobjects.c:465 RSP: 0018:ffff8801db307cf0 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000100000001 RCX: 0000000020000003 RDX: 0000000000000000 RSI: ffffffff844c6720 RDI: 0000000100000019 RBP: ffff8801db307da8 R08: ffffffff8533df90 R09: 0000000000000001 R10: 0000000000000001 R11: ffff8801d9a08000 R12: 1ffff1003b660fa0 R13: ffffffff85a2c7e8 R14: ffff8801bea07df8 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff668854db8 CR3: 00000001c29f0000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000000000092 ffffffff844c6720 0000000041b58ab3 ffffffff84209747 ffffffff81e6f9b0 ffff8801d9a08000 ffffed003b34111b ffff8801d9a088e0 ffff8801db319658 0000000000000003 ffff8801db307d80 ffffffff812296c2 Call Trace: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 7583 at include/linux/uaccess.h:15 pagefault_disabled_dec include/linux/uaccess.h:15 [inline]() WARNING: CPU: 0 PID: 7583 at include/linux/uaccess.h:15 pagefault_enable include/linux/uaccess.h:42 [inline]() WARNING: CPU: 0 PID: 7583 at include/linux/uaccess.h:15 __probe_kernel_read+0x1b9/0x200 mm/maccess.c:35()