random: sshd: uninitialized urandom read (32 bytes read, 113 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 ffff8800b4821738 by task syzkaller084794/3322 CPU: 0 PID: 3322 Comm: syzkaller084794 Not tainted 4.4.111-g3301b55 #17 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 481ccd75ed0821b5 ffff8800b477f830 ffffffff81d0509d ffffea0002d20800 ffff8800b4821738 0000000000000000 ffff8800b4821738 0000000000000000 ffff8800b477f868 ffffffff814fd433 ffff8800b4821738 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_address_description+0x73/0x260 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report+0x285/0x370 mm/kasan/report.c:408 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [] __lock_acquire+0x387e/0x4b50 kernel/locking/lockdep.c:3092 [] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592 [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline] [] _raw_spin_lock_irqsave+0x4e/0x70 kernel/locking/spinlock.c:159 [] remove_wait_queue+0x14/0x40 kernel/sched/wait.c:49 [] ep_remove_wait_queue fs/eventpoll.c:530 [inline] [] ep_unregister_pollwait.isra.6+0xa8/0x220 fs/eventpoll.c:548 [] ep_remove+0x41/0x290 fs/eventpoll.c:711 [] eventpoll_release_file+0xc5/0x140 fs/eventpoll.c:935 [] eventpoll_release include/linux/eventpoll.h:61 [inline] [] __fput+0x521/0x6d0 fs/file_table.c:199 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x104/0x180 kernel/task_work.c:115 [] exit_task_work include/linux/task_work.h:21 [inline] [] do_exit+0x871/0x2a20 kernel/exit.c:755 [] do_group_exit+0x108/0x320 kernel/exit.c:885 [] SYSC_exit_group kernel/exit.c:896 [inline] [] SyS_exit_group+0x1d/0x20 kernel/exit.c:894 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 Allocated by task 3322: [] 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+0xad/0xe0 mm/kasan/kasan.c:616 [] kmem_cache_alloc_trace+0x100/0x2b0 mm/slub.c:2642 [] kmalloc include/linux/slab.h:476 [inline] [] kzalloc include/linux/slab.h:620 [inline] [] binder_get_thread+0x181/0x7a0 drivers/android/binder.c:4452 [] binder_poll+0x4a/0x210 drivers/android/binder.c:4555 [] ep_item_poll fs/eventpoll.c:806 [inline] [] ep_insert fs/eventpoll.c:1319 [inline] [] SYSC_epoll_ctl fs/eventpoll.c:1934 [inline] [] SyS_epoll_ctl+0x10b1/0x2050 fs/eventpoll.c:1833 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 Freed by task 3322: [] 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] [] kfree+0xfc/0x300 mm/slub.c:3749 [] binder_free_thread drivers/android/binder.c:4480 [inline] [] binder_thread_dec_tmpref+0x1c1/0x250 drivers/android/binder.c:2036 [] binder_thread_release+0x27d/0x540 drivers/android/binder.c:4544 [] binder_ioctl+0xb94/0x12e0 drivers/android/binder.c:4760 [] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline] [] compat_SyS_ioctl+0x28a/0x2540 fs/compat_ioctl.c:1544 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 The buggy address belongs to the object at ffff8800b4821680 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 184 bytes inside of 512-byte region [ffff8800b4821680, ffff8800b4821880) The buggy address belongs to the page: BUG: unable to handle kernel paging request at fffffffd283aa300 IP: [] cpuacct_charge+0x155/0x390 kernel/sched/cpuacct.c:247 PGD 420f067 PUD 0 Oops: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 176 Comm: kworker/1:1 Not tainted 4.4.111-g3301b55 #17 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events vmstat_shepherd task: ffff8800bb9d0000 task.stack: ffff8800bb9a8000 RIP: 0010:[] [] cpuacct_charge+0x155/0x390 kernel/sched/cpuacct.c:247 RSP: 0018:ffff8800bb9af890 EFLAGS: 00010046 RAX: 1ffffffff0854dff RBX: 0000000000018528 RCX: ffffffff847ea080 RDX: fffffbffa5075460 RSI: fffffffd283aa300 RDI: ffffffff842a6ff8 RBP: ffff8800bb9af8d8 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 1ffff10017735ede R12: ffffffff842a6f20 R13: dffffc0000000000 R14: 0000000030e290e8 R15: ffffffffb4778050 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffd283aa300 CR3: 00000001d091c000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8122a4a0 ffff8800bb9af8c0 0000000000000046 0000000000000003 ffff8801d14b9820 ffffffff83843900 0000000030e290e8 ffff8801d14b9870 ffff8801d14b97c0 ffff8800bb9af928 ffffffff811dc017 ffff8801db21f4c0 Call Trace: [] update_curr+0x2c7/0x6c0 kernel/sched/fair.c:882 [] enqueue_entity kernel/sched/fair.c:3511 [inline] [] enqueue_task_fair+0x313/0x2940 kernel/sched/fair.c:4694 [] enqueue_task kernel/sched/core.c:856 [inline] [] activate_task+0x148/0x270 kernel/sched/core.c:872 [] ttwu_activate kernel/sched/core.c:1734 [inline] [] ttwu_do_activate.constprop.131+0xbf/0x1e0 kernel/sched/core.c:1787 [] ttwu_queue kernel/sched/core.c:1932 [inline] [] try_to_wake_up+0x68d/0xf60 kernel/sched/core.c:2066 [] wake_up_process+0x15/0x20 kernel/sched/core.c:2140 [] wake_up_worker kernel/workqueue.c:846 [inline] [] insert_work+0x171/0x210 kernel/workqueue.c:1318 [] __queue_work+0x3dc/0xea0 kernel/workqueue.c:1433 [] __queue_delayed_work+0x237/0x390 kernel/workqueue.c:1495 [] queue_delayed_work_on+0x59/0xb0 kernel/workqueue.c:1533 [] vmstat_shepherd+0x1c9/0x230 mm/vmstat.c:1488 [] process_one_work+0x7d7/0x16e0 kernel/workqueue.c:2064 [] worker_thread+0xdf/0xfe0 kernel/workqueue.c:2196 [] kthread+0x268/0x300 kernel/kthread.c:211 [] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:494 Code: 49 8d bc 24 d8 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 9e 01 00 00 49 8b 9c 24 d8 00 00 00 80 3a 00 0f 85 0a 02 00 00 <4a> 03 1c f9 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 cf 01 00 RIP [] cpuacct_charge+0x155/0x390 kernel/sched/cpuacct.c:247 RSP CR2: fffffffd283aa300 ---[ end trace 8b587a4047cfcc46 ]---