[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.885721] random: sshd: uninitialized urandom read (32 bytes read, 34 bits of entropy available) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.162460] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 23.376140] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 24.634367] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. 2018/07/18 06:47:48 parsed 1 programs 2018/07/18 06:47:51 executed programs: 0 [ 47.707595] IPVS: Creating netns size=2552 id=1 [ 47.774642] IPVS: Creating netns size=2552 id=2 [ 47.828025] IPVS: Creating netns size=2552 id=3 [ 47.891929] IPVS: Creating netns size=2552 id=4 [ 47.945217] IPVS: Creating netns size=2552 id=5 [ 48.013385] IPVS: Creating netns size=2552 id=6 [ 48.106166] IPVS: Creating netns size=2552 id=7 [ 48.181121] IPVS: Creating netns size=2552 id=8 2018/07/18 06:47:56 executed programs: 219 2018/07/18 06:48:01 executed programs: 451 2018/07/18 06:48:06 executed programs: 670 2018/07/18 06:48:11 executed programs: 890 2018/07/18 06:48:16 executed programs: 1121 2018/07/18 06:48:21 executed programs: 1352 2018/07/18 06:48:26 executed programs: 1573 [ 85.680350] ================================================================== [ 85.687765] BUG: KASAN: use-after-free in l2tp_session_create+0xde0/0x1030 [ 85.694758] Read of size 4 at addr ffff8801d4528010 by task syz-executor6/10828 [ 85.702179] [ 85.703784] CPU: 0 PID: 10828 Comm: syz-executor6 Not tainted 4.4.141-gbda6b6e #6 [ 85.711490] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 85.720824] 0000000000000000 e263a7f440881c80 ffff8800b59e7a30 ffffffff81e0e16d [ 85.728842] ffffea0007514a00 ffff8801d4528010 0000000000000000 ffff8801d4528010 [ 85.736845] ffff8800acb98048 ffff8800b59e7a68 ffffffff81515a76 ffff8801d4528010 [ 85.744848] Call Trace: [ 85.747431] [] dump_stack+0xc1/0x124 [ 85.752778] [] print_address_description+0x6c/0x216 [ 85.759430] [] kasan_report.cold.7+0x175/0x2f7 [ 85.765642] [] ? l2tp_session_create+0xde0/0x1030 [ 85.772108] [] __asan_report_load4_noabort+0x14/0x20 [ 85.778846] [] l2tp_session_create+0xde0/0x1030 [ 85.785147] [] ? l2tp_session_create+0xadc/0x1030 [ 85.791625] [] pppol2tp_connect+0x10f0/0x1910 [ 85.797759] [] ? pppol2tp_recv+0x320/0x320 [ 85.803634] [] ? security_socket_connect+0x8f/0xc0 [ 85.810197] [] SYSC_connect+0x1b8/0x300 [ 85.815801] [] ? SYSC_bind+0x280/0x280 [ 85.821328] [] ? get_unused_fd_flags+0xd0/0xd0 [ 85.827555] [] ? compat_SyS_get_robust_list+0x310/0x310 [ 85.834553] [] ? SyS_socket+0x121/0x1b0 [ 85.840162] [] ? move_addr_to_kernel+0x50/0x50 [ 85.846382] [] SyS_connect+0x24/0x30 [ 85.851727] [] ? SyS_accept+0x30/0x30 [ 85.857161] [] do_fast_syscall_32+0x326/0x8b0 [ 85.863293] [] sysenter_flags_fixed+0xd/0x17 [ 85.869327] [ 85.870944] Allocated by task 10828: [ 85.874637] [] save_stack_trace+0x26/0x50 [ 85.880533] [] save_stack+0x43/0xd0 [ 85.885906] [] kasan_kmalloc+0xc7/0xe0 [ 85.891552] [] __kmalloc+0x124/0x310 [ 85.897015] [] l2tp_session_create+0x39/0x1030 [ 85.903360] [] pppol2tp_connect+0x10f0/0x1910 [ 85.909602] [] SYSC_connect+0x1b8/0x300 [ 85.915320] [] SyS_connect+0x24/0x30 [ 85.920779] [] do_fast_syscall_32+0x326/0x8b0 [ 85.927025] [] sysenter_flags_fixed+0xd/0x17 [ 85.933181] [ 85.934785] Freed by task 10817: [ 85.938124] [] save_stack_trace+0x26/0x50 [ 85.944023] [] save_stack+0x43/0xd0 [ 85.949417] [] kasan_slab_free+0x72/0xc0 [ 85.955221] [] kfree+0xf4/0x310 [ 85.960613] [] l2tp_session_free+0x170/0x200 [ 85.966774] [] l2tp_tunnel_closeall+0x2b9/0x350 [ 85.973206] [] l2tp_udp_encap_destroy+0x8b/0xf0 [ 85.979633] [] udpv6_destroy_sock+0xb1/0xd0 [ 85.985713] [] sk_common_release+0x6d/0x300 [ 85.991785] [] udp_lib_close+0x15/0x20 [ 85.997417] [] inet_release+0xff/0x1d0 [ 86.003055] [] inet6_release+0x50/0x70 [ 86.008701] [] sock_release+0x96/0x1c0 [ 86.014342] [] sock_close+0x16/0x20 [ 86.019720] [] __fput+0x235/0x6f0 [ 86.024935] [] ____fput+0x15/0x20 [ 86.030132] [] task_work_run+0x10f/0x190 [ 86.035953] [] exit_to_usermode_loop+0x13d/0x160 [ 86.042452] [] do_fast_syscall_32+0x620/0x8b0 [ 86.048692] [] sysenter_flags_fixed+0xd/0x17 [ 86.054861] [ 86.056467] The buggy address belongs to the object at ffff8801d4528000 [ 86.056467] which belongs to the cache kmalloc-512 of size 512 [ 86.069122] The buggy address is located 16 bytes inside of [ 86.069122] 512-byte region [ffff8801d4528000, ffff8801d4528200) [ 86.080885] The buggy address belongs to the page: [ 86.086439] swap_dup: Bad swap file entry 7fffc400ea2940 [ 86.092SeaBIOS (version 1.8.2-20171012_061934-google) Total RAM Size = 0x00000001e0000000 = 7680 MiB CPUs found: 2 Max CPUs supported: 256 found virtio-scsi at 0:3 virtio-scsi vendor='Google' product='PersistentDisk' rev='1' type=0 removable=0 virtio-scsi blksize=512 sectors=4194304 = 2048 MiB drive 0x000f2290: PCHS=0/0/0 translation=lba LCHS=520/128/63 s=4194304 Booting from Hard Disk 0... early console in decompress_kernel input_data: 0x0000000003b5126e input_len: 0x00000000014cc987 output: 0x0000000001000000 output_len: 0x0000000004008a90 run_size: 0x0000000005752000 Decompressing Linux... Parsing ELF... done. Booting the kernel. [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] Initializing cgroup subsys cpuacct [ 0.000000] Initializing cgroup subsys schedtune [ 0.000000] Linux version 4.4.141-gbda6b6e (syzkaller@ci) (gcc version 8.0.1 20180413 (experimental) (GCC) ) #6 SMP PREEMPT Wed Jul 18 05:06:29 UTC 2018 [ 0.000000] Command line: BOOT_IMAGE=/vmlinuz root=/dev/sda1 console=ttyS0 earlyprintk=serial vsyscall=native rodata=n ftrace_dump_on_oops=orig_cpu oops=panic panic_on_warn=1 nmi_watchdog=panic panic=86400 workqueue.watchdog_thresh=140 nopti [ 0.000000] KERNEL supported cpus: [ 0.000000] Intel GenuineIntel [ 0.000000] AMD AuthenticAMD [ 0.000000] Centaur CentaurHauls [ 0.000000] x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256 [ 0.000000] x86/fpu: Supporting XSAVE feature 0x01: 'x87 floating point registers' [ 0.000000] x86/fpu: Supporting XSAVE feature 0x02: 'SSE registers' [ 0.000000] x86/fpu: Supporting XSAVE feature 0x04: 'AVX registers' [ 0.000000] x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format. [ 0.000000] e820: BIOS-provided physical RAM map: [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable [ 0.000000] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000bfff2fff] usable [ 0.000000] BIOS-e820: [mem 0x00000000bfff3000-0x00000000bfffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fffbc000-0x00000000ffffffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000021fffffff] usable [ 0.000000] bootconsole [earlyser0] enabled [ 0.000000] NX (Execute Disable) protection: active [ 0.000000] SMBIOS 2.4 present. [ 0.000000] Hypervisor detected: KVM [ 0.000000] Kernel/User page tables isolation: disabled [ 0.000000] e820: last_pfn = 0x220000 max_arch_pfn = 0x400000000 [ 0.000000] x86/PAT: Configuration [0-7]: WB WC UC- UC WB WC UC- WT [ 0.000000] e820: last_pfn = 0xbfff3 max_arch_pfn = 0x400000000 [ 0.000000] found SMP MP-table at [mem 0x000f2310-0x000f231f] mapped at [ffff8800000f2310] [ 0.000000] Scanning 1 areas for low memory corruption [ 0.000000] Using GB pages for direct mapping [ 0.000000] ACPI: Early table checksum verification disabled [ 0.000000] ACPI: RSDP 0x00000000000F22D0 000014 (v00 Google) [ 0.000000] ACPI: RSDT 0x00000000BFFF3430 000038 (v01 Google GOOGRSDT 00000001 GOOG 00000001) [ 0.000000] ACPI: FACP 0x00000000BFFFCF60 0000F4 (v02 Google GOOGFACP 00000001 GOOG 00000001) [ 0.000000] ACPI: DSDT 0x00000000BFFF3470 0017B2 (v01 Google GOOGDSDT 00000001 GOOG 00000001) [ 0.000000] ACPI: FACS 0x00000000BFFFCF00 000040 [ 0.000000] ACPI: FACS 0x00000000BFFFCF00 000040 [ 0.000000] ACPI: SSDT 0x00000000BFFF65F0 00690D (v01 Google GOOGSSDT 00000001 GOOG 00000001) [ 0.000000] ACPI: APIC 0x00000000BFFF5D10 000076 (v01 Google GOOGAPIC 00000001 GOOG 00000001) [ 0.000000] ACPI: WAET 0x00000000BFFF5CE0 000028 (v01 Google GOOGWAET 00000001 GOOG 00000001) [ 0.000000] ACPI: SRAT 0x00000000BFFF4C30 0000C8 (v01 Google GOOGSRAT 00000001 GOOG 00000001) [ 0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00 [ 0.000000] kvm-clock: cpu 0, msr 2:1fffd001, primary cpu clock [ 0.000000] kvm-clock: using sched offset of 2323902099 cycles [ 0.000000] clocksource: kvm-clock: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x0000000000001000-0x0000000000ffffff] [ 0.000000] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] [ 0.000000] Normal [mem 0x0000000100000000-0x000000021fffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000001000-0x000000000009efff] [ 0.000000] node 0: [mem 0x0000000000100000-0x00000000bfff2fff] [ 0.000000] node 0: [mem 0x0000000100000000-0x000000021fffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000001000-0x000000021fffffff] [ 0.000000] kasan: KernelAddressSanitizer initialized [ 0.000000] ACPI: PM-Timer IO Port: 0xb008 [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0xff] dfl dfl lint[0x1]) [ 0.000000] IOAPIC[0]: apic_id 0, version 17, address 0xfec00000, GSI 0-23 [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 5 global_irq 5 high level) [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level) [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 10 global_irq 10 high level) [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 11 global_irq 11 high level) [ 0.000000] Using ACPI (MADT) for SMP configuration information [ 0.000000] smpboot: Allowing 2 CPUs, 0 hotplug CPUs [ 0.000000] PM: Registered nosave memory: [mem 0x00000000-0x00000fff] [ 0.000000] PM: Registered nosave memory: [mem 0x0009f000-0x0009ffff] [ 0.000000] PM: Registered nosave memory: [mem 0x000a0000-0x000effff] [ 0.000000] PM: Registered nosave memory: [mem 0x000f0000-0x000fffff] [ 0.000000] PM: Registered nosave memory: [mem 0xbfff3000-0xbfffffff] [ 0.000000] PM: Registered nosave memory: [mem 0xc0000000-0xfffbbfff] [ 0.000000] PM: Registered nosave memory: [mem 0xfffbc000-0xffffffff] [ 0.000000] e820: [mem 0xc0000000-0xfffbbfff] available for PCI devices [ 0.000000] Booting paravirtualized kernel on KVM [ 0.000000] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns [ 0.000000] setup_percpu: NR_CPUS:64 nr_cpumask_bits:64 nr_cpu_ids:2 nr_node_ids:1 [ 0.000000] PERCPU: Embedded 42 pages/cpu @ffff8801db200000 s134024 r8192 d29816 u1048576 [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 1935227 [ 0.000000] Kernel command line: BOOT_IMAGE=/vmlinuz root=/dev/sda1 console=ttyS0 earlyprintk=serial vsyscall=native rodata=n ftrace_dump_on_oops=orig_cpu oops=panic panic_on_warn=1 nmi_watchdog=panic panic=86400 workqueue.watchdog_thresh=140 nopti [ 0.000000] PID hash table entries: 4096 (order: 3, 32768 bytes) [ 0.000000] Dentry cache hash table entries: 1048576 (order: 11, 8388608 bytes) [ 0.000000] Inode-cache hash table entries: 524288 (order: 10, 4194304 bytes) [ 0.000000] Memory: 6579092K/7863876K available (41762K kernel code, 6303K rwdata, 9052K rodata, 1864K init, 23696K bss, 1284784K reserved, 0K cma-reserved) [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1 [ 0.000000] Running RCU self tests [ 0.000000] Preemptible hierarchical RCU implementation. [ 0.000000] RCU lockdep checking is enabled. [ 0.000000] Build-time adjustment of leaf fanout to 64. [ 0.000000] RCU restricting CPUs from NR_CPUS=64 to nr_cpu_ids=2. [ 0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=64, nr_cpu_ids=2 [ 0.000000] NR_IRQS:4352 nr_irqs:440 16 [ 0.000000] console [ttyS0] enabled [ 0.000000] console [ttyS0] enabled [ 0.000000] bootconsole [earlyser0] disabled [ 0.000000] bootconsole [earlyser0] disabled [ 0.000000] Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar [ 0.000000] ... MAX_LOCKDEP_SUBCLASSES: 8 [ 0.000000] ... MAX_LOCK_DEPTH: 48 [ 0.000000] ... MAX_LOCKDEP_KEYS: 8191 [ 0.000000] ... CLASSHASH_SIZE: 4096 [ 0.000000] ... MAX_LOCKDEP_ENTRIES: 32768 [ 0.000000] ... MAX_LOCKDEP_CHAINS: 65536 [ 0.000000] ... CHAINHASH_SIZE: 32768 [ 0.000000] memory used by lock dependency info: 8159 kB [ 0.000000] per task-struct memory footprint: 1920 bytes [ 0.000000] tsc: Detected 2300.000 MHz processor [ 1.232530] Calibrating delay loop (skipped) preset value.. 4600.00 BogoMIPS (lpj=23000000) [ 1.233713] pid_max: default: 32768 minimum: 301 [ 1.234420] ACPI: Core revision 20150930 [ 1.645377] ACPI: 2 ACPI AML tables successfully acquired and loaded [ 1.646737] Security Framework initialized [ 1.647317] SELinux: Initializing. [ 1.648072] AppArmor: AppArmor disabled by boot time parameter [ 1.649017] Mount-cache hash table entries: 16384 (order: 5, 131072 bytes) [ 1.650008] Mountpoint-cache hash table entries: 16384 (order: 5, 131072 bytes) [ 1.653728] Initializing cgroup subsys io [ 1.654351] Initializing cgroup subsys freezer [ 1.654997] Initializing cgroup subsys hugetlb [ 1.655695] Initializing cgroup subsys debug [ 1.656468] CPU: Physical Processor ID: 0 [ 1.658402] mce: CPU supports 32 MCE banks [ 1.659204] Last level iTLB entries: 4KB 1024, 2MB 1024, 4MB 1024 [ 1.660052] Last level dTLB entries: 4KB 1024, 2MB 1024, 4MB 1024, 1GB 4 [ 1.660978] Spectre V2 : Mitigation: Full generic retpoline [ 1.664199] Freeing SMP alternatives memory: 48K [ 1.674026] ..TIMER: vector=0x30 apic1=0 pin1=0 apic2=-1 pin2=-1 [ 1.791593] smpboot: CPU0: Intel(R) Xeon(R) CPU @ 2.30GHz (family: 0x6, model: 0x3f, stepping: 0x0) [ 1.793047] Performance Events: unsupported p6 CPU model 63 no PMU driver, software events only. [ 1.881994] x86: Booting SMP configuration: [ 1.882881] .... node #0, CPUs: #1 [ 1.883872] kvm-clock: cpu 1, msr 2:1fffd041, secondary cpu clock [ 1.888773] x86: Booted up 1 node, 2 CPUs [ 1.889377] smpboot: Total of 2 processors activated (9200.00 BogoMIPS) [ 1.893494] devtmpfs: initialized [ 1.903876] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns [ 1.905292] futex hash table entries: 512 (order: 4, 65536 bytes) [ 1.907061] xor: automatically using best checksumming function: [ 1.920026] kworker/u4:0 (21) used greatest stack depth: 27920 bytes left [ 2.001608] avx : 23521.200 MB/sec [ 2.002836] RTC time: 6:48:34, date: 07/18/18 [ 2.006047] NET: Registered protocol family 16 [ 2.007222] schedtune: init normalization constants... [ 2.007962] schedtune: no energy model data [ 2.008538] schedtune: disabled! [ 2.041847] cpuidle: using governor ladder [ 2.071669] cpuidle: using governor menu [ 2.073047] ACPI: bus type PCI registered [ 2.073699] acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5 [ 2.076793] PCI: Using configuration type 1 for base access [ 2.088399] kworker/u4:1 (40) used greatest stack depth: 27616 bytes left [ 2.090101] kworker/u4:1 (48) used greatest stack depth: 27424 bytes left [ 2.234512] kworker/u4:2 (317) used greatest stack depth: 27024 bytes left [ 2.551574] raid6: sse2x1 gen() 4660 MB/s [ 2.721563] raid6: sse2x1 xor() 2603 MB/s [ 2.891550] raid6: sse2x2 gen() 7011 MB/s [ 3.061532] raid6: sse2x2 xor() 4067 MB/s [ 3.231529] raid6: sse2x4 gen() 8677 MB/s [ 3.401516] raid6: sse2x4 xor() 5234 MB/s [ 3.571505] raid6: avx2x1 gen() 9421 MB/s [ 3.741490] raid6: avx2x2 gen() 14666 MB/s [ 3.911483] raid6: avx2x4 gen() 19215 MB/s [ 3.912159] raid6: using algorithm avx2x4 gen() 19215 MB/s [ 3.912931] raid6: using avx2x2 recovery algorithm [ 3.914308] ACPI: Added _OSI(Module Device) [ 3.914960] ACPI: Added _OSI(Processor Device) [ 3.915583] ACPI: Added _OSI(3.0 _SCP Extensions) [ 3.916229] ACPI: Added _OSI(Processor Aggregator Device) [ 3.943090] ACPI: Executed 2 blocks of module-level executable AML code [ 4.904592] ACPI: Interpreter enabled [ 4.905635] ACPI: (supports S0 S3 S4 S5) [ 4.906197] ACPI: Using IOAPIC for interrupt routing [ 4.907398] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug [ 6.196486] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff]) [ 6.197479] acpi PNP0A03:00: _OSC: OS supports [ASPM ClockPM Segments MSI] [ 6.198873] acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM [ 6.199939] acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended PCI configuration space under this bridge. [ 6.231416] PCI host bridge to bus 0000:00 [ 6.232195] pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window] [ 6.233233] pci_bus 0000:00: root bus resource [io 0x0d00-0xffff window] [ 6.234260] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window] [ 6.235391] pci_bus 0000:00: root bus resource [mem 0xc0000000-0xfebfffff window] [ 6.236515] pci_bus 0000:00: root bus resource [bus 00-ff] [ 6.285927] pci 0000:00:01.3: quirk: [io 0xb000-0xb03f] claimed by PIIX4 ACPI [ 6.401587] ACPI: PCI Interrupt Link [LNKA] (IRQs 5 *10 11) [ 6.409431] ACPI: PCI Interrupt Link [LNKB] (IRQs 5 *10 11) [ 6.416893] ACPI: PCI Interrupt Link [LNKC] (IRQs 5 10 *11) [ 6.424507] ACPI: PCI Interrupt Link [LNKD] (IRQs 5 10 *11) [ 6.429665] ACPI: PCI Interrupt Link [LNKS] (IRQs *9)