================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3c66/0x5270 kernel/locking/lockdep.c:3092 Read of size 8 at addr ffff8801bcc15e20 by task syz-executor7/17950 CPU: 1 PID: 17950 Comm: syz-executor7 Not tainted 4.4.145-g2241aa9 #14 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 feb96fbef6d90241 ffff8800bba7fa30 ffffffff81e123cd ffffea0006f30400 ffff8801bcc15e20 0000000000000000 ffff8801bcc15e20 0000000000000000 ffff8800bba7fa68 ffffffff81517d66 ffff8801bcc15e20 Call Trace: [<ffffffff81e123cd>] __dump_stack lib/dump_stack.c:15 [inline] [<ffffffff81e123cd>] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [<ffffffff81517d66>] print_address_description+0x6c/0x216 mm/kasan/report.c:252 [<ffffffff81518085>] kasan_report_error mm/kasan/report.c:351 [inline] [<ffffffff81518085>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408 [<ffffffff814fbb74>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [<ffffffff81234f26>] __lock_acquire+0x3c66/0x5270 kernel/locking/lockdep.c:3092 [<ffffffff81237d0e>] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592 [<ffffffff838c775a>] __raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline] [<ffffffff838c775a>] _raw_spin_lock_bh+0x3a/0x50 kernel/locking/spinlock.c:175 [<ffffffff82f2b583>] spin_lock_bh include/linux/spinlock.h:307 [inline] [<ffffffff82f2b583>] lock_sock_nested+0x43/0x120 net/core/sock.c:2451 [<ffffffff835ad430>] lock_sock include/net/sock.h:1493 [inline] [<ffffffff835ad430>] pppol2tp_release+0x50/0x310 net/l2tp/l2tp_ppp.c:493 [<ffffffff82f1ed76>] sock_release+0x96/0x1c0 net/socket.c:586 [<ffffffff82f1eeb6>] sock_close+0x16/0x20 net/socket.c:1037 [<ffffffff81525155>] __fput+0x235/0x6f0 fs/file_table.c:208 [<ffffffff81525695>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff8118e00f>] 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:253 [<ffffffff8100708e>] prepare_exit_to_usermode arch/x86/entry/common.c:284 [inline] [<ffffffff8100708e>] syscall_return_slowpath arch/x86/entry/common.c:349 [inline] [<ffffffff8100708e>] do_syscall_32_irqs_on arch/x86/entry/common.c:399 [inline] [<ffffffff8100708e>] do_fast_syscall_32+0x61e/0x8b0 arch/x86/entry/common.c:460 [<ffffffff838c9e43>] sysenter_flags_fixed+0xd/0x1a Allocated by task 17969: [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [<ffffffff814fac23>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [<ffffffff814faf07>] set_track mm/kasan/kasan.c:524 [inline] [<ffffffff814faf07>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616 [<ffffffff814f7624>] __kmalloc+0x124/0x310 mm/slub.c:3613 [<ffffffff82f2a444>] kmalloc include/linux/slab.h:481 [inline] [<ffffffff82f2a444>] sk_prot_alloc+0x204/0x300 net/core/sock.c:1354 [<ffffffff82f2fe1a>] sk_alloc+0x3a/0x3a0 net/core/sock.c:1419 [<ffffffff835a9353>] pppol2tp_create+0x33/0x1f0 net/l2tp/l2tp_ppp.c:551 [<ffffffff828f5f76>] pppox_create+0xf6/0x200 drivers/net/ppp/pppox.c:121 [<ffffffff82f252a0>] __sock_create+0x2f0/0x5f0 net/socket.c:1177 [<ffffffff82f257d0>] sock_create net/socket.c:1217 [inline] [<ffffffff82f257d0>] SYSC_socket net/socket.c:1247 [inline] [<ffffffff82f257d0>] SyS_socket+0xf0/0x1b0 net/socket.c:1227 [<ffffffff81006d94>] do_syscall_32_irqs_on arch/x86/entry/common.c:393 [inline] [<ffffffff81006d94>] do_fast_syscall_32+0x324/0x8b0 arch/x86/entry/common.c:460 [<ffffffff838c9e43>] sysenter_flags_fixed+0xd/0x1a Freed by task 17987: [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [<ffffffff814fac23>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [<ffffffff814fb552>] set_track mm/kasan/kasan.c:524 [inline] [<ffffffff814fb552>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [<ffffffff814f8a54>] slab_free_hook mm/slub.c:1383 [inline] [<ffffffff814f8a54>] slab_free_freelist_hook mm/slub.c:1405 [inline] [<ffffffff814f8a54>] slab_free mm/slub.c:2859 [inline] [<ffffffff814f8a54>] kfree+0xf4/0x310 mm/slub.c:3749 [<ffffffff82f342d7>] sk_prot_free net/core/sock.c:1391 [inline] [<ffffffff82f342d7>] sk_destruct+0x407/0x4c0 net/core/sock.c:1472 [<ffffffff82f343df>] __sk_free+0x4f/0x220 net/core/sock.c:1480 [<ffffffff82f345e0>] sk_free+0x30/0x40 net/core/sock.c:1491 [<ffffffff835ac90f>] sock_put include/net/sock.h:1639 [inline] [<ffffffff835ac90f>] pppol2tp_session_sock_put+0x5f/0x70 net/l2tp/l2tp_ppp.c:286 [<ffffffff835a518c>] l2tp_tunnel_closeall+0x23c/0x350 net/l2tp/l2tp_core.c:1277 [<ffffffff835a5d1b>] l2tp_udp_encap_destroy+0x8b/0xf0 net/l2tp/l2tp_core.c:1300 [<ffffffff83497d21>] udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1421 [<ffffffff82f3465d>] sk_common_release+0x6d/0x300 net/core/sock.c:2680 [<ffffffff834969d5>] udp_lib_close+0x15/0x20 include/net/udp.h:190 [<ffffffff832fe2cf>] inet_release+0xff/0x1d0 net/ipv4/af_inet.c:435 [<ffffffff83420fd0>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:424 [<ffffffff82f1ed76>] sock_release+0x96/0x1c0 net/socket.c:586 [<ffffffff82f1eeb6>] sock_close+0x16/0x20 net/socket.c:1037 [<ffffffff81525155>] __fput+0x235/0x6f0 fs/file_table.c:208 [<ffffffff81525695>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff8118e00f>] 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:253 [<ffffffff8100708e>] prepare_exit_to_usermode arch/x86/entry/common.c:284 [inline] [<ffffffff8100708e>] syscall_return_slowpath arch/x86/entry/common.c:349 [inline] [<ffffffff8100708e>] do_syscall_32_irqs_on arch/x86/entry/common.c:399 [inline] [<ffffffff8100708e>] do_fast_syscall_32+0x61e/0x8b0 arch/x86/entry/common.c:460 [<ffffffff838c9e43>] sysenter_flags_fixed+0xd/0x1a The buggy address belongs to the object at ffff8801bcc15d80 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff8801bcc15d80, ffff8801bcc16580) 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 4.4.145-g2241aa9 (syzkaller@ci) (gcc version 8.0.1 20180413 (experimental) (GCC) ) #14 SMP PREEMPT Wed Aug 1 08:09:05 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 0x000f2310-0x000f231f] mapped at [ffff8800000f2310] Scanning 1 areas for low memory corruption Using GB pages for direct mapping ACPI: Early table checksum verification disabled ACPI: RSDP 0x00000000000F22D0 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 2330327278 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 (41784K 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 : 23314.800 MB/sec RTC time: 11:05:47, date: 08/01/18 NET: Registered protocol family 16 schedtune: init normalization constants... schedtune: no energy model data schedtune: disabled! kworker/u4:0 (29) used greatest stack depth: 27616 bytes left 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/u4:1 (48) used greatest stack depth: 27424 bytes left kworker/u4:0 (346) used greatest stack depth: 27024 bytes left raid6: sse2x1 gen() 4637 MB/s raid6: sse2x1 xor() 2331 MB/s raid6: sse2x2 gen() 7444 MB/s raid6: sse2x2 xor() 4183 MB/s raid6: sse2x4 gen() 9835 MB/s raid6: sse2x4 xor() 5668 MB/s raid6: avx2x1 gen() 9013 MB/s raid6: avx2x2 gen() 14467 MB/s raid6: avx2x4 gen() 18853 MB/s raid6: using algorithm avx2x4 gen() 18853 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 ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff]) acpi PNP0A03:00: _OSC: OS supports [ASPM ClockPM Segments MSI] acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended PCI configuration space under this bridge. PCI host bridge to bus 0000:00 pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window] pci_bus 0000:00: root bus resource [io 0x0d00-0xffff window] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window] pci_bus 0000:00: root bus resource [mem 0xc0000000-0xfebfffff window] pci_bus 0000:00: root bus resource [bus 00-ff] pci 0000:00:01.3: quirk: [io 0xb000-0xb03f] claimed by PIIX4 ACPI ACPI: PCI Interrupt Link [LNKA] (IRQs 5 *10 11) ACPI: PCI Interrupt Link [LNKB] (IRQs 5 *10 11) ACPI: PCI Interrupt Link [LNKC] (IRQs 5 10 *11) ACPI: PCI Interrupt Link [LNKD] (IRQs 5 10 *11) ACPI: PCI Interrupt Link [LNKS] (IRQs *9)