[ 21.304061] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.479209] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 26.070068] random: sshd: uninitialized urandom read (32 bytes read, 42 bits of entropy available) [ 27.089648] random: sshd: uninitialized urandom read (32 bytes read, 126 bits of entropy available) [ 27.210455] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.40' (ECDSA) to the list of known hosts. executing program [ 32.769691] ================================================================== [ 32.777074] BUG: KASAN: use-after-free in ip6_xmit+0x1a2c/0x1a70 [ 32.783187] Read of size 8 at addr ffff8801d2392798 by task syzkaller071815/3776 [ 32.790683] [ 32.792280] CPU: 0 PID: 3776 Comm: syzkaller071815 Not tainted 4.4.120-gd63fdf6 #28 [ 32.800038] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.809360] 0000000000000000 a1236742e5dbc1cd ffff8800aac2f6a8 ffffffff81d0408d [ 32.817320] ffffea000748e480 ffff8801d2392798 0000000000000000 ffff8801d2392798 [ 32.825276] 0000000000000040 ffff8800aac2f6e0 ffffffff814fe143 ffff8801d2392798 [ 32.833239] Call Trace: [ 32.835800] [] dump_stack+0xc1/0x124 [ 32.841146] [] print_address_description+0x73/0x260 [ 32.847781] [] kasan_report+0x285/0x370 [ 32.853379] [] ? ip6_xmit+0x1a2c/0x1a70 [ 32.858970] [] __asan_report_load8_noabort+0x14/0x20 [ 32.865688] [] ip6_xmit+0x1a2c/0x1a70 [ 32.871105] [] ? save_trace+0xe0/0x270 [ 32.876609] [] ? pskb_expand_head+0x28b/0x980 [ 32.882721] [] ? ip6_finish_output2+0x1c60/0x1c60 [ 32.889179] [] ? __lock_is_held+0xa1/0xf0 [ 32.894946] [] ? ipv4_dst_check+0x111/0x160 [ 32.900884] [] ? __sk_dst_check+0x148/0x260 [ 32.906821] [] inet6_csk_xmit+0x246/0x480 [ 32.912585] [] ? inet6_csk_xmit+0x100/0x480 [ 32.918534] [] ? inet6_csk_update_pmtu+0x160/0x160 [ 32.925085] [] ? udp6_set_csum+0x336/0xa80 [ 32.930936] [] l2tp_xmit_skb+0xc2f/0xea0 [ 32.936613] [] pppol2tp_sendmsg+0x584/0x7f0 [ 32.942553] [] ? selinux_socket_sendmsg+0x3f/0x50 [ 32.949014] [] ? pppol2tp_release+0x310/0x310 [ 32.955126] [] sock_sendmsg+0xca/0x110 [ 32.960632] [] ___sys_sendmsg+0x6c1/0x7c0 [ 32.966398] [] ? copy_msghdr_from_user+0x550/0x550 [ 32.972948] [] ? check_preemption_disabled+0x3b/0x200 [ 32.979756] [] ? do_huge_pmd_anonymous_page+0x549/0xa10 [ 32.986745] [] ? _raw_spin_unlock+0x2c/0x50 [ 32.992683] [] ? do_huge_pmd_anonymous_page+0x3dd/0xa10 [ 32.999664] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.006384] [] ? __fget_light+0xa3/0x1e0 [ 33.012060] [] ? __fdget+0x18/0x20 [ 33.017216] [] __sys_sendmsg+0xd3/0x190 [ 33.022807] [] ? SyS_shutdown+0x1b0/0x1b0 [ 33.028576] [] ? __do_page_fault+0x380/0xa00 [ 33.034601] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 33.041406] [] SyS_sendmsg+0x2d/0x50 [ 33.046741] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 33.053284] [ 33.054879] Allocated by task 3754: [ 33.058470] [] save_stack_trace+0x26/0x50 [ 33.064353] [] save_stack+0x43/0xd0 [ 33.069713] [] kasan_kmalloc+0xad/0xe0 [ 33.075329] [] kasan_slab_alloc+0x12/0x20 [ 33.081212] [] kmem_cache_alloc+0xba/0x290 [ 33.087176] [] dst_alloc+0x11f/0x1a0 [ 33.092623] [] rt_dst_alloc+0x78/0x430 [ 33.098244] [] __ip_route_output_key_hash+0xa4e/0x2390 [ 33.105250] [] __ip4_datagram_connect+0xa15/0x1150 [ 33.111909] [] __ip6_datagram_connect+0x4d9/0x1950 [ 33.118575] [] ip6_datagram_connect+0x2f/0x50 [ 33.124804] [] inet_dgram_connect+0x16b/0x1f0 [ 33.131030] [] SYSC_connect+0x1b6/0x310 [ 33.136747] [] SyS_connect+0x24/0x30 [ 33.142209] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 33.148876] [ 33.150473] Freed by task 3: [ 33.153455] [] save_stack_trace+0x26/0x50 [ 33.159342] [] save_stack+0x43/0xd0 [ 33.164706] [] kasan_slab_free+0x72/0xc0 [ 33.170500] [] kmem_cache_free+0xc7/0x320 [ 33.176379] [] dst_destroy+0x20e/0x330 [ 33.181997] [] dst_destroy_rcu+0x15/0x40 [ 33.187788] [] rcu_process_callbacks+0x7f4/0x14a0 [ 33.194360] [] __do_softirq+0x227/0xa38 [ 33.200068] [ 33.201667] The buggy address belongs to the object at ffff8801d2392780 [ 33.201667] which belongs to the cache ip_dst_cache of size 208 [ 33.214375] The buggy address is located 24 bytes inside of [ 33.214375] 208-byte region [ffff8801d2392780, ffff8801d2392850) [ 33.226125] The buggy address belongs to the page: SeaBIOS (version 1.8.2-20171120_144221-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 0x000f2360: PCHS=0/0/0 translation=lba LCHS=520/128/63 s=4194304 Booting from Hard Disk 0... early console in decompress_kernel input_data: 0x00000000037cb26e input_len: 0x0000000001423b2c output: 0x0000000001000000 output_len: 0x0000000003bdaa40 run_size: 0x0000000005310000 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 4.4.120-gd63fdf6 (syzkaller@ci) (gcc version 7.1.1 20170620 (GCC) ) #28 SMP PREEMPT Tue Mar 6 13:16:06 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=120 [ 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] x86/fpu: Using 'eager' FPU context switches. [ 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] 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 0x000f23e0-0x000f23ef] mapped at [ffff8800000f23e0] [ 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 0x00000000000F23A0 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 2813582918 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=120 [ 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: 6581404K/7863876K available (40422K kernel code, 6136K rwdata, 8808K rodata, 1848K init, 23616K bss, 1282472K reserved, 0K cma-reserved) [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1 [ 0.000000] Kernel/User page tables isolation: enabled [ 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 [ 1.089579] Calibrating delay loop (skipped) preset value.. 4600.00 BogoMIPS (lpj=23000000) [ 1.090735] pid_max: default: 32768 minimum: 301 [ 1.091436] ACPI: Core revision 20150930 [ 1.510680] ACPI: 2 ACPI AML tables successfully acquired and loaded [ 1.512572] Security Framework initialized [ 1.513162] SELinux: Initializing. [ 1.513810] AppArmor: AppArmor disabled by boot time parameter [ 1.514723] Mount-cache hash table entries: 16384 (order: 5, 131072 bytes) [ 1.515648] Mountpoint-cache hash table entries: 16384 (order: 5, 131072 bytes) [ 1.519341] Initializing cgroup subsys io [ 1.519936] Initializing cgroup subsys freezer [ 1.520583] Initializing cgroup subsys hugetlb [ 1.521206] Initializing cgroup subsys debug [ 1.521968] CPU: Physical Processor ID: 0 [ 1.523719] mce: CPU supports 32 MCE banks [ 1.524456] Last level iTLB entries: 4KB 1024, 2MB 1024, 4MB 1024 [ 1.525283] Last level dTLB entries: 4KB 1024, 2MB 1024, 4MB 1024, 1GB 4 [ 1.526187] Spectre V2 : Vulnerable: Minimal generic ASM retpoline [ 1.529348] Freeing SMP alternatives memory: 44K [ 1.539267] ..TIMER: vector=0x30 apic1=0 pin1=0 apic2=-1 pin2=-1 [ 1.658860] smpboot: CPU0: Intel(R) Xeon(R) CPU @ 2.30GHz (family: 0x6, model: 0x3f, stepping: 0x0) [ 1.660374] Performance Events: unsupported p6 CPU model 63 no PMU driver, software events only. [ 1.749100] x86: Booting SMP configuration: [ 1.749751] .... node #0, CPUs: #1 [ 1.750556] kvm-clock: cpu 1, msr 2:1fffd041, secondary cpu clock [ 1.755239] x86: Booted up 1 node, 2 CPUs [ 1.755821] smpboot: Total of 2 processors activated (9200.00 BogoMIPS) [ 1.760428] devtmpfs: initialized [ 1.769867] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns [ 1.771247] futex hash table entries: 512 (order: 4, 65536 bytes) [ 1.772872] xor: automatically using best checksumming function: [ 1.776065] kworker/u4:0 (21) used greatest stack depth: 27944 bytes left [ 1.868863] avx : 21700.800 MB/sec [ 1.870026] RTC time: 3:11:47, date: 03/07/18 [ 1.872275] NET: Registered protocol family 16 [ 1.873342] schedtune: init normalization constants... [ 1.874041] schedtune: no energy model data [ 1.874653] schedtune: disabled! [ 1.909042] cpuidle: using governor ladder [ 1.938879] cpuidle: using governor menu [ 1.940104] ACPI: bus type PCI registered [ 1.940664] acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5 [ 1.943463] PCI: Using configuration type 1 for base access [ 1.955073] kworker/u4:0 (42) used greatest stack depth: 27448 bytes left [ 2.368861] raid6: sse2x1 gen() 4729 MB/s [ 2.538806] raid6: sse2x1 xor() 2602 MB/s [ 2.708791] raid6: sse2x2 gen() 7062 MB/s [ 2.878771] raid6: sse2x2 xor() 4081 MB/s [ 3.048760] raid6: sse2x4 gen() 8706 MB/s [ 3.218747] raid6: sse2x4 xor() 5299 MB/s [ 3.388730] raid6: avx2x1 gen() 9489 MB/s [ 3.558713] raid6: avx2x2 gen() 14768 MB/s [ 3.728698] raid6: avx2x4 gen() 19387 MB/s [ 3.729385] raid6: using algorithm avx2x4 gen() 19387 MB/s [ 3.730184] raid6: using avx2x2 recovery algorithm [ 3.731485] ACPI: Added _OSI(Module Device) [ 3.732126] ACPI: Added _OSI(Processor Device) [ 3.732770] ACPI: Added _OSI(3.0 _SCP Extensions) [ 3.733433] ACPI: Added _OSI(Processor Aggregator Device) [ 3.758968] ACPI: Executed 2 blocks of module-level executable AML code [ 4.596355] ACPI: Interpreter enabled [ 4.597321] ACPI: (supports S0 S3 S4 S5) [ 4.597946] ACPI: Using IOAPIC for interrupt routing [ 4.599080] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug