random: sshd: uninitialized urandom read (32 bytes read, 98 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 ffff8800b45a79b8 by task syzkaller313966/3324 CPU: 0 PID: 3324 Comm: syzkaller313966 Not tainted 4.4.111-g7902639 #18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 1325eac2e8036e02 ffff8800b4e5f850 ffffffff81d0509d ffffea0002d16980 ffff8800b45a79b8 0000000000000000 ffff8800b45a79b8 0000000000000000 ffff8800b4e5f888 ffffffff814fd433 ffff8800b45a79b8 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_free+0x93/0x1c0 fs/eventpoll.c:765 [] ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:797 [] __fput+0x233/0x6d0 fs/file_table.c:208 [] ____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 3324: [] 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 3324: [] 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 ffff8800b45a7900 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 184 bytes inside of 512-byte region [ffff8800b45a7900, ffff8800b45a7b00) The buggy address belongs to the page: kasan: CONFIG_KASAN_INLINE enabled page:ffffea0002d16980 count:-30719 mapcount:-739378039 mapping:ffff8800b456b600 index:0xffff8801d2768700 flags: 0xffff8801d3edf700(owner_priv_1|arch_1|reserved|private_2|writeback|head|swapcache|mappedtodisk|swapbacked|unevictable|uncached|compound_lock) page dumped because: VM_BUG_ON_PAGE(PageSlab(page)) ------------[ cut here ]------------ kernel BUG at include/linux/mm.h:460! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 3324 Comm: syzkaller313966 Not tainted 4.4.111-g7902639 #18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d1fd97c0 task.stack: ffff8800b4e58000 RIP: 0010:[] [] dump_page mm/debug.c:105 [inline] RIP: 0010:[] [] page_mapcount include/linux/mm.h:460 [inline] RIP: 0010:[] [] dump_page_badflags+0x191/0x250 mm/debug.c:85 RSP: 0018:ffff88009b000040 EFLAGS: 00010082 RAX: ffff8801d1fd97c0 RBX: ffffea0002d16980 RCX: ffffffff8148f96c RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff8801d1fda02c RBP: ffff88009b000070 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000002 R11: fffffbfff0ad8dc9 R12: 0000000000000000 R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000080a27c0 CR3: 000000000420c000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000000000000 ffffea0002d16980 0000000000000000 ffffffff838a8360 0000000000000000 0000000000000000 ffff88009b0000b0 ffffffff8148f991 0000000000000000 ffffea0002d16980 0000000000000000 ffffffff838a8360 Call Trace: Code: 46 e8 14 05 ed ff 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 00 05 ed ff 31 d2 48 c7 c6 60 83 8a 83 48 89 df e8 6f fe ff ff <0f> 0b e8 d8 e0 06 00 e9 21 ff ff ff 89 4d d4 e8 cb e0 06 00 8b RIP [] dump_page mm/debug.c:105 [inline] RIP [] page_mapcount include/linux/mm.h:460 [inline] RIP [] dump_page_badflags+0x191/0x250 mm/debug.c:85 RSP ---[ end trace a013dcb7f1579663 ]---