================================================================== BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:141 [inline] BUG: KASAN: use-after-free in ip6_xmit+0x177c/0x1a00 net/ipv6/ip6_output.c:237 Read of size 8 at addr ffff8800ad6c7658 by task syz-executor3/15970 CPU: 0 PID: 15970 Comm: syz-executor3 Not tainted 4.4.147-ga5fc665 #16 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 cfe5ecb65f831571 ffff8800ba47f548 ffffffff81e12a4d ffffea0002b5b1c0 ffff8800ad6c7658 0000000000000000 ffff8800ad6c7658 0000000000001200 ffff8800ba47f580 ffffffff81517fd6 ffff8800ad6c7658 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_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [] ip6_dst_idev include/net/ip6_fib.h:141 [inline] [] ip6_xmit+0x177c/0x1a00 net/ipv6/ip6_output.c:237 [] inet6_csk_xmit+0x245/0x490 net/ipv6/inet6_connection_sock.c:176 [] l2tp_xmit_core net/l2tp/l2tp_core.c:1084 [inline] [] l2tp_xmit_skb+0xbeb/0xeb0 net/l2tp/l2tp_core.c:1179 [] pppol2tp_sendmsg+0x4e0/0x7d0 net/l2tp/l2tp_ppp.c:355 [] sock_sendmsg_nosec net/socket.c:626 [inline] [] sock_sendmsg+0xcc/0x110 net/socket.c:636 [] ___sys_sendmsg+0x441/0x880 net/socket.c:1963 [] __sys_sendmmsg+0x1d4/0x2e0 net/socket.c:2041 [] C_SYSC_sendmmsg net/compat.c:728 [inline] [] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:725 [] do_syscall_32_irqs_on arch/x86/entry/common.c:393 [inline] [] do_fast_syscall_32+0x324/0x8b0 arch/x86/entry/common.c:460 [] sysenter_flags_fixed+0xd/0x1a Allocated by task 13403: [] 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 [] dst_alloc+0xb5/0x1a0 net/core/dst.c:210 [] rt_dst_alloc+0x78/0x430 net/ipv4/route.c:1478 [] __mkroute_output net/ipv4/route.c:2132 [inline] [] __ip_route_output_key_hash+0x9ac/0x2380 net/ipv4/route.c:2344 [] __ip_route_output_key include/net/route.h:124 [inline] [] ip_route_output_flow+0x29/0xa0 net/ipv4/route.c:2431 [] udp_sendmsg+0x1480/0x1c70 net/ipv4/udp.c:1040 [] udpv6_sendmsg+0x12cd/0x24c0 net/ipv6/udp.c:1173 [] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755 [] sock_sendmsg_nosec net/socket.c:626 [inline] [] sock_sendmsg+0xcc/0x110 net/socket.c:636 [] ___sys_sendmsg+0x441/0x880 net/socket.c:1963 [] __sys_sendmmsg+0x1d4/0x2e0 net/socket.c:2041 [] C_SYSC_sendmmsg net/compat.c:728 [inline] [] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:725 [] do_syscall_32_irqs_on arch/x86/entry/common.c:393 [inline] [] do_fast_syscall_32+0x324/0x8b0 arch/x86/entry/common.c:460 [] sysenter_flags_fixed+0xd/0x1a Freed by task 3: [] 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 [] dst_destroy.part.6+0x1f5/0x330 net/core/dst.c:270 [] dst_destroy net/core/dst.c:252 [inline] [] dst_destroy_rcu+0x15/0x40 net/core/dst.c:295 [] __rcu_reclaim kernel/rcu/rcu.h:118 [inline] [] rcu_do_batch kernel/rcu/tree.c:2705 [inline] [] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline] [] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline] [] rcu_process_callbacks+0x927/0x1440 kernel/rcu/tree.c:2957 [] __do_softirq+0x22c/0xa1a kernel/softirq.c:273 The buggy address belongs to the object at ffff8800ad6c7640 which belongs to the cache ip_dst_cache of size 208 The buggy address is located 24 bytes inside of 208-byte region [ffff8800ad6c7640, ffff8800ad6c7710) The buggy address belongs to the page: Initializing cgroup subsys cpuset Initializing cgroup subsys cpu Initializing cgroup subsys cpuacct Initializing cgroup subsys schedtune Linux version 4.4.147-ga5fc665 (syzkaller@ci) (gcc version 8.0.1 20180413 (experimental) (GCC) ) #16 SMP PREEMPT Thu Aug 9 15:00:53 UTC 2018 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 KERNEL supported cpus: Intel GenuineIntel AMD AuthenticAMD Centaur CentaurHauls x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256 x86/fpu: Supporting XSAVE feature 0x01: 'x87 floating point registers' x86/fpu: Supporting XSAVE feature 0x02: 'SSE registers' x86/fpu: Supporting XSAVE feature 0x04: 'AVX registers' x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format. e820: BIOS-provided physical RAM map: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved BIOS-e820: [mem 0x0000000000100000-0x00000000bfff2fff] usable BIOS-e820: [mem 0x00000000bfff3000-0x00000000bfffffff] reserved BIOS-e820: [mem 0x00000000fffbc000-0x00000000ffffffff] reserved BIOS-e820: [mem 0x0000000100000000-0x000000021fffffff] usable bootconsole [earlyser0] enabled NX (Execute Disable) protection: active SMBIOS 2.4 present. Hypervisor detected: KVM Kernel/User page tables isolation: disabled e820: last_pfn = 0x220000 max_arch_pfn = 0x400000000 x86/PAT: Configuration [0-7]: WB WC UC- UC WB WC UC- WT e820: last_pfn = 0xbfff3 max_arch_pfn = 0x400000000 found SMP MP-table at [mem 0x000f2300-0x000f230f] mapped at [ffff8800000f2300] Scanning 1 areas for low memory corruption Using GB pages for direct mapping ACPI: Early table checksum verification disabled ACPI: RSDP 0x00000000000F22C0 000014 (v00 Google) ACPI: RSDT 0x00000000BFFF3430 000038 (v01 Google GOOGRSDT 00000001 GOOG 00000001) ACPI: FACP 0x00000000BFFFCF60 0000F4 (v02 Google GOOGFACP 00000001 GOOG 00000001) ACPI: DSDT 0x00000000BFFF3470 0017B2 (v01 Google GOOGDSDT 00000001 GOOG 00000001) ACPI: FACS 0x00000000BFFFCF00 000040 ACPI: FACS 0x00000000BFFFCF00 000040 ACPI: SSDT 0x00000000BFFF65F0 00690D (v01 Google GOOGSSDT 00000001 GOOG 00000001) ACPI: APIC 0x00000000BFFF5D10 000076 (v01 Google GOOGAPIC 00000001 GOOG 00000001) ACPI: WAET 0x00000000BFFF5CE0 000028 (v01 Google GOOGWAET 00000001 GOOG 00000001) ACPI: SRAT 0x00000000BFFF4C30 0000C8 (v01 Google GOOGSRAT 00000001 GOOG 00000001) kvm-clock: Using msrs 4b564d01 and 4b564d00 kvm-clock: cpu 0, msr 2:1fffd001, primary cpu clock kvm-clock: using sched offset of 2006315623 cycles clocksource: kvm-clock: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns Zone ranges: DMA [mem 0x0000000000001000-0x0000000000ffffff] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] Normal [mem 0x0000000100000000-0x000000021fffffff] Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000000001000-0x000000000009efff] node 0: [mem 0x0000000000100000-0x00000000bfff2fff] node 0: [mem 0x0000000100000000-0x000000021fffffff] Initmem setup node 0 [mem 0x0000000000001000-0x000000021fffffff] kasan: KernelAddressSanitizer initialized ACPI: PM-Timer IO Port: 0xb008 ACPI: LAPIC_NMI (acpi_id[0xff] dfl dfl lint[0x1]) IOAPIC[0]: apic_id 0, version 17, address 0xfec00000, GSI 0-23 ACPI: INT_SRC_OVR (bus 0 bus_irq 5 global_irq 5 high level) ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level) ACPI: INT_SRC_OVR (bus 0 bus_irq 10 global_irq 10 high level) ACPI: INT_SRC_OVR (bus 0 bus_irq 11 global_irq 11 high level) Using ACPI (MADT) for SMP configuration information smpboot: Allowing 2 CPUs, 0 hotplug CPUs PM: Registered nosave memory: [mem 0x00000000-0x00000fff] PM: Registered nosave memory: [mem 0x0009f000-0x0009ffff] PM: Registered nosave memory: [mem 0x000a0000-0x000effff] PM: Registered nosave memory: [mem 0x000f0000-0x000fffff] PM: Registered nosave memory: [mem 0xbfff3000-0xbfffffff] PM: Registered nosave memory: [mem 0xc0000000-0xfffbbfff] PM: Registered nosave memory: [mem 0xfffbc000-0xffffffff] e820: [mem 0xc0000000-0xfffbbfff] available for PCI devices Booting paravirtualized kernel on KVM clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns setup_percpu: NR_CPUS:64 nr_cpumask_bits:64 nr_cpu_ids:2 nr_node_ids:1 PERCPU: Embedded 42 pages/cpu @ffff8801db200000 s134152 r8192 d29688 u1048576 Built 1 zonelists in Zone order, mobility grouping on. Total pages: 1935227 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 PID hash table entries: 4096 (order: 3, 32768 bytes) Dentry cache hash table entries: 1048576 (order: 11, 8388608 bytes) Inode-cache hash table entries: 524288 (order: 10, 4194304 bytes) Memory: 6579080K/7863876K available (41786K kernel code, 6308K rwdata, 9064K rodata, 1868K init, 23696K bss, 1284796K reserved, 0K cma-reserved) SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1 Running RCU self tests Preemptible hierarchical RCU implementation. RCU lockdep checking is enabled. Build-time adjustment of leaf fanout to 64. RCU restricting CPUs from NR_CPUS=64 to nr_cpu_ids=2. RCU: Adjusting geometry for rcu_fanout_leaf=64, nr_cpu_ids=2 NR_IRQS:4352 nr_irqs:440 16 console [ttyS0] enabled console [ttyS0] enabled bootconsole [earlyser0] disabled bootconsole [earlyser0] disabled Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar ... MAX_LOCKDEP_SUBCLASSES: 8 ... MAX_LOCK_DEPTH: 48 ... MAX_LOCKDEP_KEYS: 8191 ... CLASSHASH_SIZE: 4096 ... MAX_LOCKDEP_ENTRIES: 32768 ... MAX_LOCKDEP_CHAINS: 65536 ... CHAINHASH_SIZE: 32768 memory used by lock dependency info: 8159 kB per task-struct memory footprint: 1920 bytes tsc: Detected 2300.000 MHz processor Calibrating delay loop (skipped) preset value.. 4600.00 BogoMIPS (lpj=23000000) pid_max: default: 32768 minimum: 301 ACPI: Core revision 20150930 ACPI: 2 ACPI AML tables successfully acquired and loaded Security Framework initialized SELinux: Initializing. AppArmor: AppArmor disabled by boot time parameter Mount-cache hash table entries: 16384 (order: 5, 131072 bytes) Mountpoint-cache hash table entries: 16384 (order: 5, 131072 bytes) Initializing cgroup subsys io Initializing cgroup subsys freezer Initializing cgroup subsys hugetlb Initializing cgroup subsys debug CPU: Physical Processor ID: 0 mce: CPU supports 32 MCE banks Last level iTLB entries: 4KB 1024, 2MB 1024, 4MB 1024 Last level dTLB entries: 4KB 1024, 2MB 1024, 4MB 1024, 1GB 4 Spectre V2 : Mitigation: Full generic retpoline Speculative Store Bypass: Vulnerable Freeing SMP alternatives memory: 48K ..TIMER: vector=0x30 apic1=0 pin1=0 apic2=-1 pin2=-1 smpboot: CPU0: Intel(R) Xeon(R) CPU @ 2.30GHz (family: 0x6, model: 0x3f, stepping: 0x0) Performance Events: unsupported p6 CPU model 63 no PMU driver, software events only. x86: Booting SMP configuration: .... node #0, CPUs: #1 kvm-clock: cpu 1, msr 2:1fffd041, secondary cpu clock x86: Booted up 1 node, 2 CPUs smpboot: Total of 2 processors activated (9200.00 BogoMIPS) devtmpfs: initialized clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns futex hash table entries: 512 (order: 4, 65536 bytes) xor: automatically using best checksumming function: kworker/u4:0 (21) used greatest stack depth: 27920 bytes left avx : 25086.000 MB/sec RTC time: 6:02:16, date: 08/14/18 NET: Registered protocol family 16 schedtune: init normalization constants... schedtune: no energy model data schedtune: disabled! cpuidle: using governor ladder cpuidle: using governor menu ACPI: bus type PCI registered acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5 PCI: Using configuration type 1 for base access kworker/u4:0 (47) used greatest stack depth: 27424 bytes left kworker/u4:0 (120) used greatest stack depth: 27024 bytes left raid6: sse2x1 gen() 4547 MB/s raid6: sse2x1 xor() 2428 MB/s raid6: sse2x2 gen() 7164 MB/s raid6: sse2x2 xor() 4091 MB/s raid6: sse2x4 gen() 9132 MB/s raid6: sse2x4 xor() 5559 MB/s raid6: avx2x1 gen() 9010 MB/s raid6: avx2x2 gen() 13332 MB/s raid6: avx2x4 gen() 17033 MB/s raid6: using algorithm avx2x4 gen() 17033 MB/s raid6: using avx2x2 recovery algorithm ACPI: Added _OSI(Module Device) ACPI: Added _OSI(Processor Device) ACPI: Added _OSI(3.0 _SCP Extensions) ACPI: Added _OSI(Processor Aggregator Device) ACPI: Executed 2 blocks of module-level executable AML code ACPI: Interpreter enabled ACPI: (supports S0 S3 S4 S5) ACPI: Using IOAPIC for interrupt routing PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug