random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) random: nonblocking pool is initialized IPVS: Creating netns size=2552 id=1 ================================================================== BUG: KASAN: use-after-free in l2tp_session_queue_purge+0xf4/0x100 net/l2tp/l2tp_core.c:830 Read of size 4 at addr ffff8800b4612f00 by task syz-executor0/3758 CPU: 0 PID: 3758 Comm: syz-executor0 Not tainted 4.4.131-g3702e76 #37 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 1a39095e99df717c ffff8801cc007c78 ffffffff81e0df8d ffffea0002d18480 ffff8800b4612f00 0000000000000000 ffff8800b4612f00 ffffffff82f18cb0 ffff8801cc007cb0 ffffffff8151520c ffff8800b4612f00 Call Trace: [<ffffffff81e0df8d>] __dump_stack lib/dump_stack.c:15 [inline] [<ffffffff81e0df8d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [<ffffffff8151520c>] print_address_description+0x6c/0x216 mm/kasan/report.c:252 [<ffffffff8151552b>] kasan_report_error mm/kasan/report.c:351 [inline] [<ffffffff8151552b>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408 [<ffffffff814f9004>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428 [<ffffffff83598784>] l2tp_session_queue_purge+0xf4/0x100 net/l2tp/l2tp_core.c:830 [<ffffffff835a52bf>] pppol2tp_release+0x1ff/0x310 net/l2tp/l2tp_ppp.c:509 [<ffffffff82f18b86>] sock_release+0x96/0x1c0 net/socket.c:586 [<ffffffff82f18cc6>] sock_close+0x16/0x20 net/socket.c:1037 [<ffffffff815225f5>] __fput+0x235/0x6f0 fs/file_table.c:208 [<ffffffff81522b35>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff8118bb8f>] task_work_run+0x10f/0x190 kernel/task_work.c:115 [<ffffffff8100362d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [<ffffffff8100362d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:252 [<ffffffff81007090>] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline] [<ffffffff81007090>] syscall_return_slowpath arch/x86/entry/common.c:348 [inline] [<ffffffff81007090>] do_syscall_32_irqs_on arch/x86/entry/common.c:398 [inline] [<ffffffff81007090>] do_fast_syscall_32+0x620/0x8b0 arch/x86/entry/common.c:459 [<ffffffff838c16aa>] sysenter_flags_fixed+0xd/0x17 Allocated by task 3758: [<ffffffff810341d6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [<ffffffff814f80d3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [<ffffffff814f83b7>] set_track mm/kasan/kasan.c:524 [inline] [<ffffffff814f83b7>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616 [<ffffffff814f4ad4>] __kmalloc+0x124/0x310 mm/slub.c:3613 [<ffffffff8359dbc9>] kmalloc include/linux/slab.h:481 [inline] [<ffffffff8359dbc9>] kzalloc include/linux/slab.h:620 [inline] [<ffffffff8359dbc9>] l2tp_session_create+0x39/0x1030 net/l2tp/l2tp_core.c:1748 [<ffffffff835a28d0>] pppol2tp_connect+0x10f0/0x1910 net/l2tp/l2tp_ppp.c:725 [<ffffffff82f1d5a8>] SYSC_connect+0x1b8/0x300 net/socket.c:1557 [<ffffffff82f1fee4>] SyS_connect+0x24/0x30 net/socket.c:1538 [<ffffffff81006d96>] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline] [<ffffffff81006d96>] do_fast_syscall_32+0x326/0x8b0 arch/x86/entry/common.c:459 [<ffffffff838c16aa>] sysenter_flags_fixed+0xd/0x17 Freed by task 3756: [<ffffffff810341d6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [<ffffffff814f80d3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [<ffffffff814f8a02>] set_track mm/kasan/kasan.c:524 [inline] [<ffffffff814f8a02>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [<ffffffff814f5f04>] slab_free_hook mm/slub.c:1383 [inline] [<ffffffff814f5f04>] slab_free_freelist_hook mm/slub.c:1405 [inline] [<ffffffff814f5f04>] slab_free mm/slub.c:2859 [inline] [<ffffffff814f5f04>] kfree+0xf4/0x310 mm/slub.c:3749 [<ffffffff8359ab30>] l2tp_session_free+0x170/0x200 net/l2tp/l2tp_core.c:1676 [<ffffffff8359cee9>] l2tp_session_dec_refcount_1 net/l2tp/l2tp_core.h:293 [inline] [<ffffffff8359cee9>] l2tp_tunnel_closeall+0x2b9/0x350 net/l2tp/l2tp_core.c:1279 [<ffffffff8359d9fb>] l2tp_udp_encap_destroy+0x8b/0xf0 net/l2tp/l2tp_core.c:1300 [<ffffffff8348fff1>] udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1421 [<ffffffff82f2e45d>] sk_common_release+0x6d/0x300 net/core/sock.c:2680 [<ffffffff8348eca5>] udp_lib_close+0x15/0x20 include/net/udp.h:190 [<ffffffff832f695f>] inet_release+0xff/0x1d0 net/ipv4/af_inet.c:435 [<ffffffff834194f0>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:424 [<ffffffff82f18b86>] sock_release+0x96/0x1c0 net/socket.c:586 [<ffffffff82f18cc6>] sock_close+0x16/0x20 net/socket.c:1037 [<ffffffff815225f5>] __fput+0x235/0x6f0 fs/file_table.c:208 [<ffffffff81522b35>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff8118bb8f>] task_work_run+0x10f/0x190 kernel/task_work.c:115 [<ffffffff8100362d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [<ffffffff8100362d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:252 [<ffffffff81007090>] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline] [<ffffffff81007090>] syscall_return_slowpath arch/x86/entry/common.c:348 [inline] [<ffffffff81007090>] do_syscall_32_irqs_on arch/x86/entry/common.c:398 [inline] [<ffffffff81007090>] do_fast_syscall_32+0x620/0x8b0 arch/x86/entry/common.c:459 [<ffffffff838c16aa>] sysenter_flags_fixed+0xd/0x17 The buggy address belongs to the object at ffff8800b4612f00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff8800b4612f00, ffff8800b4613100) The buggy address belongs to the page: BUG: unable to handle kernel paging request at fffffffd27aad040 IP: [<ffffffff81224a95>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247 PGD 440f067 PUD 0 Oops: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 3750 Comm: syz-executor0 Not tainted 4.4.131-g3702e76 #37 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800b10a8000 task.stack: ffff8800b0958000 RIP: 0010:[<ffffffff81224a95>] [<ffffffff81224a95>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247 RSP: 0018:ffff8800b095f938 EFLAGS: 00010046 RAX: 1ffffffff089500f RBX: 0000000000018528 RCX: ffffffff84a14840 RDX: fffffbffa4f55a08 RSI: fffffffd27aad040 RDI: ffffffff844a8078 RBP: ffff8800b095f978 R08: ffff8800b10a89a0 R09: 0000000000000001 R10: 0000000000000001 R11: ffff8800b10a8000 R12: ffffffff844a7fa0 R13: dffffc0000000000 R14: 0000000035d50af0 R15: ffffffffb4613100 FS: 0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:0000000009838900 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: fffffffd27aad040 CR3: 00000000b47d1000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff812249a0 0000000000000046 0000000000000003 ffff8800b0a3b060 ffff8800b0a3b000 0000000035d50af0 ffff8800b0a3b0b0 0000000000000000 ffff8800b095f9c0 ffffffff811d9049 0000000000000005 ffff8801db21f4d8 Call Trace: [<ffffffff811d9049>] update_curr+0x2c9/0x6d0 kernel/sched/fair.c:882 [<ffffffff811e424a>] enqueue_entity kernel/sched/fair.c:3512 [inline] [<ffffffff811e424a>] enqueue_task_fair+0x2fa/0x2790 kernel/sched/fair.c:4695 [<ffffffff811bb72d>] enqueue_task kernel/sched/core.c:858 [inline] [<ffffffff811bb72d>] activate_task+0x14d/0x280 kernel/sched/core.c:874 [<ffffffff811bc75f>] ttwu_activate kernel/sched/core.c:1736 [inline] [<ffffffff811bc75f>] ttwu_do_activate.constprop.109+0xbf/0x1e0 kernel/sched/core.c:1789 [<ffffffff811bf970>] ttwu_queue kernel/sched/core.c:1934 [inline] [<ffffffff811bf970>] try_to_wake_up+0x660/0xf00 kernel/sched/core.c:2068 [<ffffffff811c24c0>] wake_up_state+0x10/0x20 kernel/sched/core.c:2148 [<ffffffff81155994>] signal_wake_up_state+0x44/0x70 kernel/signal.c:659 [<ffffffff8115602b>] signal_wake_up include/linux/sched.h:3323 [inline] [<ffffffff8115602b>] complete_signal+0x62b/0x790 kernel/signal.c:942 [<ffffffff81157575>] __send_signal+0x4d5/0x11b0 kernel/signal.c:1080 [<ffffffff8115829a>] send_signal+0x4a/0xc0 kernel/signal.c:1096 [<ffffffff8115a984>] do_send_sig_info+0xa4/0x130 kernel/signal.c:1151 [<ffffffff8115b836>] group_send_sig_info+0xf6/0x170 kernel/signal.c:1273 [<ffffffff8115b940>] __kill_pgrp_info+0x90/0x120 kernel/signal.c:1291 [<ffffffff8115be05>] kill_something_info kernel/signal.c:1397 [inline] [<ffffffff8115be05>] SYSC_kill+0x225/0x5a0 kernel/signal.c:2867 [<ffffffff81161dcc>] SyS_kill+0x1c/0x30 kernel/signal.c:2857 [<ffffffff81006d96>] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline] [<ffffffff81006d96>] do_fast_syscall_32+0x326/0x8b0 arch/x86/entry/common.c:459 [<ffffffff838c16aa>] sysenter_flags_fixed+0xd/0x17 Code: 49 8d bc 24 d8 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 c4 01 00 00 49 8b 9c 24 d8 00 00 00 80 3a 00 0f 85 8f 01 00 00 <4a> 03 1c f9 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 be 01 00 RIP [<ffffffff81224a95>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247 RSP <ffff8800b095f938> CR2: fffffffd27aad040 ---[ end trace a5d992d22c744530 ]---