l2tp_core: tunl 4194308: sockfd_lookup(fd=5) returned -9 ========================= WARNING: held lock freed! 4.14.159-syzkaller #0 Not tainted ------------------------- syz-executor.0/31419 is freeing memory ffff888095d5eec0-ffff888095d5f6bf, with a lock still held there! kobject: 'loop3' (ffff8880a4a58960): kobject_uevent_env (sk_lock-AF_PPPOX){+.+.}, at: [] lock_sock include/net/sock.h:1462 [inline] (sk_lock-AF_PPPOX){+.+.}, at: [] pppol2tp_release+0x45/0x290 net/l2tp/l2tp_ppp.c:476 2 locks held by syz-executor.0/31419: #0: (&sb->s_type->i_mutex_key#11){+.+.}, at: [] inode_lock include/linux/fs.h:718 [inline] #0: (&sb->s_type->i_mutex_key#11){+.+.}, at: [] __sock_release+0x7d/0x2a0 net/socket.c:601 #1: (sk_lock-AF_PPPOX){+.+.}, at: [] lock_sock include/net/sock.h:1462 [inline] #1: (sk_lock-AF_PPPOX){+.+.}, at: [] pppol2tp_release+0x45/0x290 net/l2tp/l2tp_ppp.c:476 stack backtrace: CPU: 0 PID: 31419 Comm: syz-executor.0 Not tainted 4.14.159-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 kobject: 'loop3' (ffff8880a4a58960): fill_kobj_path: path = '/devices/virtual/block/loop3' Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xf7/0x13b lib/dump_stack.c:58 print_freed_lock_bug kernel/locking/lockdep.c:4459 [inline] debug_check_no_locks_freed.cold.64+0x9e/0xaa kernel/locking/lockdep.c:4492 kfree+0xb1/0x270 mm/slab.c:3812 sk_prot_free net/core/sock.c:1504 [inline] __sk_destruct+0x3e1/0x4e0 net/core/sock.c:1581 sk_destruct+0x83/0xb0 net/core/sock.c:1596 __sk_free+0x47/0x1f0 net/core/sock.c:1604 sk_free+0x23/0x30 net/core/sock.c:1615 sock_put include/net/sock.h:1653 [inline] pppol2tp_release+0x21e/0x290 net/l2tp/l2tp_ppp.c:493 __sock_release+0xc2/0x2a0 net/socket.c:602 sock_close+0x10/0x20 net/socket.c:1139 kobject: 'loop1' (ffff8880a49a0660): kobject_uevent_env __fput+0x232/0x750 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xe5/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x16a/0x1b0 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+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459f49 kobject: 'loop1' (ffff8880a49a0660): fill_kobj_path: path = '/devices/virtual/block/loop1' RSP: 002b:00007f145a067c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000459f49 RDX: 000000000000002e RSI: 0000000020000180 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f145a0686d4 R13: 00000000004c068b R14: 00000000004d2d58 R15: 00000000ffffffff ================================================================== kobject: 'loop2' (ffff8880a49ac6e0): kobject_uevent_env BUG: KASAN: use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline] BUG: KASAN: use-after-free in do_raw_spin_lock+0x1e0/0x220 kernel/locking/spinlock_debug.c:112 Read of size 4 at addr ffff888095d5ef4c by task syz-executor.0/31419 CPU: 0 PID: 31419 Comm: syz-executor.0 Not tainted 4.14.159-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+0xf7/0x13b lib/dump_stack.c:58 kobject: 'loop2' (ffff8880a49ac6e0): fill_kobj_path: path = '/devices/virtual/block/loop2' print_address_description.cold.7+0x9/0x1c9 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.8+0x11a/0x2d3 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline] do_raw_spin_lock+0x1e0/0x220 kernel/locking/spinlock_debug.c:112 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline] _raw_spin_lock_bh+0x39/0x40 kernel/locking/spinlock.c:176 spin_lock_bh include/linux/spinlock.h:322 [inline] release_sock+0x1b/0x180 net/core/sock.c:2777 pppol2tp_release+0x1f5/0x290 net/l2tp/l2tp_ppp.c:495 __sock_release+0xc2/0x2a0 net/socket.c:602 sock_close+0x10/0x20 net/socket.c:1139 __fput+0x232/0x750 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 kobject: 'loop5' (ffff8880a4ae32e0): kobject_uevent_env task_work_run+0xe5/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x16a/0x1b0 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+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459f49 RSP: 002b:00007f145a067c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000459f49 RDX: 000000000000002e RSI: 0000000020000180 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f145a0686d4 R13: 00000000004c068b R14: 00000000004d2d58 R15: 00000000ffffffff kobject: 'loop5' (ffff8880a4ae32e0): fill_kobj_path: path = '/devices/virtual/block/loop5' Allocated by task 31428: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15b/0x7b0 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] sk_prot_alloc+0x146/0x240 net/core/sock.c:1467 sk_alloc+0x30/0xc10 net/core/sock.c:1521 pppol2tp_create+0x23/0x1d0 net/l2tp/l2tp_ppp.c:534 pppox_create+0xd3/0x1f0 drivers/net/ppp/pppox.c:134 __sock_create+0x262/0x540 net/socket.c:1275 sock_create net/socket.c:1315 [inline] SYSC_socket net/socket.c:1345 [inline] SyS_socket+0xc6/0x1a0 net/socket.c:1325 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 31419: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 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:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 sk_prot_free net/core/sock.c:1504 [inline] __sk_destruct+0x3e1/0x4e0 net/core/sock.c:1581 sk_destruct+0x83/0xb0 net/core/sock.c:1596 __sk_free+0x47/0x1f0 net/core/sock.c:1604 sk_free+0x23/0x30 net/core/sock.c:1615 sock_put include/net/sock.h:1653 [inline] pppol2tp_release+0x21e/0x290 net/l2tp/l2tp_ppp.c:493 __sock_release+0xc2/0x2a0 net/socket.c:602 sock_close+0x10/0x20 net/socket.c:1139 __fput+0x232/0x750 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xe5/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x16a/0x1b0 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+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff888095d5eec0 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 140 bytes inside of 2048-byte region [ffff888095d5eec0, ffff888095d5f6c0) The buggy address belongs to the page: page:ffffea0002575780 count:1 mapcount:0 mapping:ffff888095d5e640 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000008100(slab|head) raw: 01fffc0000008100 ffff888095d5e640 0000000000000000 0000000100000003 raw: ffffea000262a1a0 ffffea0002550220 ffff8880aa800c40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888095d5ee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888095d5ee80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff888095d5ef00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888095d5ef80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888095d5f000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================