random: sshd: uninitialized urandom read (32 bytes read, 115 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 ffff8800b4d18fb8 by task syzkaller742144/3306 CPU: 0 PID: 3306 Comm: syzkaller742144 Not tainted 4.4.111-g1849cd3 #19 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 c2cbea685eb613e3 ffff8801d14b7850 ffffffff81d0509d ffffea0002d34600 ffff8800b4d18fb8 0000000000000000 ffff8800b4d18fb8 0000000000000000 ffff8801d14b7888 ffffffff814fd433 ffff8800b4d18fb8 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 3306: [] 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 3306: [] 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 ffff8800b4d18f00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 184 bytes inside of 512-byte region [ffff8800b4d18f00, ffff8800b4d19100) The buggy address belongs to the page: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 189 Comm: kworker/1:1 Not tainted 4.4.111-g1849cd3 #19 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events reg_todo task: ffff8801d94e0000 task.stack: ffff8801d9498000 RIP: 0010:[] [] find_stack lib/stackdepot.c:174 [inline] RIP: 0010:[] [] depot_save_stack+0x15f/0x640 lib/stackdepot.c:225 RSP: 0018:ffff8801d949f608 EFLAGS: 00010293 RAX: ffff8801d94e0000 RBX: 000000008d2933a5 RCX: ffffffff81dae0df RDX: 0000000000000000 RSI: 00000000024000c0 RDI: ffff8801d949f670 RBP: ffff8801d949f660 R08: ffff8801d949f670 R09: 0000000000000000 R10: 0000000000000000 R11: 1ffff1003b293efe R12: 3d5952544e554f43 R13: 00000000000933a5 R14: 0000000000000070 R15: ffff8801d949f6f4 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a0e8cf1100 CR3: 00000000b549c000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 00000000024000c0 ffff8801d949f670 ffff8801d949f688 ffff88010000000e 0000000000000000 7ec9044c7e507755 00000000024000c0 ffff8801d1697d60 00000000024000c0 ffff8801d1697d60 ffff8801da384640 ffff8801d949f890 Call Trace: [] save_stack+0xa3/0xd0 mm/kasan/kasan.c:518 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc+0xad/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+0xba/0x290 mm/slub.c:2628 [] kmem_cache_alloc_node include/linux/slab.h:350 [inline] [] __alloc_skb+0xe6/0x600 net/core/skbuff.c:218 [] alloc_skb include/linux/skbuff.h:815 [inline] [] kobject_uevent_env+0x576/0xb40 lib/kobject_uevent.c:300 [] call_crda+0x129/0x200 net/wireless/reg.c:590 [] reg_query_database net/wireless/reg.c:614 [inline] [] reg_process_hint_core net/wireless/reg.c:1908 [inline] [] reg_process_hint+0x31e/0xbe0 net/wireless/reg.c:2163 [] reg_process_pending_hints net/wireless/reg.c:2260 [inline] [] reg_todo+0x182/0x6e0 net/wireless/reg.c:2337 [] 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: 00 00 e8 c5 1d 5b ff 48 63 45 c0 48 c1 e0 03 49 89 c6 eb 12 e8 b3 1d 5b ff 4d 8b 24 24 4d 85 e4 0f 84 f8 00 00 00 e8 a1 1d 5b ff <41> 39 5c 24 08 75 e2 e8 95 1d 5b ff 8b 45 c0 41 3b 44 24 0c 75 RIP [] find_stack lib/stackdepot.c:174 [inline] RIP [] depot_save_stack+0x15f/0x640 lib/stackdepot.c:225 RSP ---[ end trace dc49d65c55c6c29d ]---