random: sshd: uninitialized urandom read (32 bytes read, 110 bits of entropy available) ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 kernel/locking/lockdep.c:3092 Read of size 8 at addr ffff8801d2e64ab8 by task syzkaller063830/3321 CPU: 0 PID: 3321 Comm: syzkaller063830 Not tainted 4.4.110-gdac1439 #13 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 bf42c1480c842397 ffff8800b4967850 ffffffff81d04e3d ffffea00074b9900 ffff8801d2e64ab8 0000000000000000 ffff8801d2e64ab8 0000000000000000 ffff8800b4967888 ffffffff814fd1f3 ffff8801d2e64ab8 Call Trace: [<ffffffff81d04e3d>] __dump_stack lib/dump_stack.c:15 [inline] [<ffffffff81d04e3d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [<ffffffff814fd1f3>] print_address_description+0x73/0x260 mm/kasan/report.c:252 [<ffffffff814fd705>] kasan_report_error mm/kasan/report.c:351 [inline] [<ffffffff814fd705>] kasan_report+0x285/0x370 mm/kasan/report.c:408 [<ffffffff814fd864>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [<ffffffff81239bde>] __lock_acquire+0x387e/0x4b50 kernel/locking/lockdep.c:3092 [<ffffffff8123c71e>] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592 [<ffffffff837751be>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline] [<ffffffff837751be>] _raw_spin_lock_irqsave+0x4e/0x70 kernel/locking/spinlock.c:159 [<ffffffff8121f0c4>] remove_wait_queue+0x14/0x40 kernel/sched/wait.c:49 [<ffffffff815f65f8>] ep_remove_wait_queue fs/eventpoll.c:530 [inline] [<ffffffff815f65f8>] ep_unregister_pollwait.isra.6+0xa8/0x220 fs/eventpoll.c:548 [<ffffffff815f7323>] ep_free+0x93/0x1c0 fs/eventpoll.c:765 [<ffffffff815f7494>] ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:797 [<ffffffff81522833>] __fput+0x233/0x6d0 fs/file_table.c:208 [<ffffffff81522d55>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff8118ba14>] task_work_run+0x104/0x180 kernel/task_work.c:115 [<ffffffff81132e11>] exit_task_work include/linux/task_work.h:21 [inline] [<ffffffff81132e11>] do_exit+0x871/0x2a20 kernel/exit.c:755 [<ffffffff81139288>] do_group_exit+0x108/0x320 kernel/exit.c:885 [<ffffffff811394bd>] SYSC_exit_group kernel/exit.c:896 [inline] [<ffffffff811394bd>] SyS_exit_group+0x1d/0x20 kernel/exit.c:894 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [<ffffffff83776f6a>] sysenter_flags_fixed+0xd/0x17 Allocated by task 3321: [<ffffffff81035d26>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [<ffffffff814fc263>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [<ffffffff814fc52d>] set_track mm/kasan/kasan.c:524 [inline] [<ffffffff814fc52d>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616 [<ffffffff814f84a0>] kmem_cache_alloc_trace+0x100/0x2b0 mm/slub.c:2642 [<ffffffff82c7e9a1>] kmalloc include/linux/slab.h:476 [inline] [<ffffffff82c7e9a1>] kzalloc include/linux/slab.h:620 [inline] [<ffffffff82c7e9a1>] binder_get_thread+0x181/0x7a0 drivers/android/binder.c:4452 [<ffffffff82c7f00a>] binder_poll+0x4a/0x210 drivers/android/binder.c:4555 [<ffffffff815fa481>] ep_item_poll fs/eventpoll.c:806 [inline] [<ffffffff815fa481>] ep_insert fs/eventpoll.c:1319 [inline] [<ffffffff815fa481>] SYSC_epoll_ctl fs/eventpoll.c:1934 [inline] [<ffffffff815fa481>] SyS_epoll_ctl+0x10b1/0x2050 fs/eventpoll.c:1833 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [<ffffffff83776f6a>] sysenter_flags_fixed+0xd/0x17 Freed by task 3321: [<ffffffff81035d26>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [<ffffffff814fc263>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [<ffffffff814fcb82>] set_track mm/kasan/kasan.c:524 [inline] [<ffffffff814fcb82>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [<ffffffff814f960c>] slab_free_hook mm/slub.c:1383 [inline] [<ffffffff814f960c>] slab_free_freelist_hook mm/slub.c:1405 [inline] [<ffffffff814f960c>] slab_free mm/slub.c:2859 [inline] [<ffffffff814f960c>] kfree+0xfc/0x300 mm/slub.c:3749 [<ffffffff82c77ef1>] binder_free_thread drivers/android/binder.c:4480 [inline] [<ffffffff82c77ef1>] binder_thread_dec_tmpref+0x1c1/0x250 drivers/android/binder.c:2036 [<ffffffff82c78a2d>] binder_thread_release+0x27d/0x540 drivers/android/binder.c:4544 [<ffffffff82c93694>] binder_ioctl+0xb94/0x12e0 drivers/android/binder.c:4760 [<ffffffff8161de7a>] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline] [<ffffffff8161de7a>] compat_SyS_ioctl+0x28a/0x2540 fs/compat_ioctl.c:1544 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [<ffffffff83776f6a>] sysenter_flags_fixed+0xd/0x17 The buggy address belongs to the object at ffff8801d2e64a00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 184 bytes inside of 512-byte region [ffff8801d2e64a00, ffff8801d2e64c00) The buggy address belongs to the page: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.110-gdac1439 #13 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801da3a17c0 task.stack: ffff8801da3b0000 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff8801db307df0 EFLAGS: 00010006 RAX: ffff8801da3a17c0 RBX: ffff8800b428fdf8 RCX: ffffffff812ac8d0 RDX: 0000000000010000 RSI: ffffffff839fd820 RDI: ffff8800b428fdf8 RBP: ffff8801db307ee0 R08: 1ffff1003a9f2561 R09: 0000000000000001 R10: 0000000000000000 R11: 1ffff1003b660f6a R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801db319640 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001d0e2c000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff812ac8d6 ffff88021fffd057 ffff88021fffd05b ffff88021fffd04f 1ffff1003b660fcb ffff8801db3196a0 ffffed003b660fca ffff8801db319700 0303fc0000000001 ffff8801db319678 ffffed003b6632d4 ffff8801db319718 Call Trace: <IRQ> [<ffffffff812aeda6>] hrtimer_interrupt+0x1a6/0x440 kernel/time/hrtimer.c:1351 [<ffffffff810b091a>] local_apic_timer_interrupt+0x6a/0xb0 arch/x86/kernel/apic/apic.c:901 [<ffffffff83778236>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:925 [<ffffffff83777190>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:725 <EOI> [<ffffffff81027e15>] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline] [<ffffffff81027e15>] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:291 [<ffffffff8102938a>] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:282 [<ffffffff81220438>] default_idle_call+0x48/0x70 kernel/sched/idle.c:93 [<ffffffff81220b45>] cpuidle_idle_call kernel/sched/idle.c:157 [inline] [<ffffffff81220b45>] cpu_idle_loop kernel/sched/idle.c:253 [inline] [<ffffffff81220b45>] cpu_startup_entry+0x605/0x820 kernel/sched/idle.c:301 [<ffffffff810ad7a4>] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242 Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8801db307df0> CR2: 0000000000000000 ---[ end trace 31fbd0b010930100 ]---