[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 15.717684] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.990423] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.436462] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.315153] random: sshd: uninitialized urandom read (32 bytes read, 110 bits of entropy available) [ 23.715599] random: sshd: uninitialized urandom read (32 bytes read, 116 bits of entropy available) Warning: Permanently added '10.128.0.9' (ECDSA) to the list of known hosts. [ 29.075832] random: sshd: uninitialized urandom read (32 bytes read, 124 bits of entropy available) executing program [ 29.187879] ================================================================== [ 29.195263] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 29.201905] Read of size 8 at addr ffff8801d2a9c0b8 by task syzkaller446647/3325 [ 29.209409] [ 29.211029] CPU: 1 PID: 3325 Comm: syzkaller446647 Not tainted 4.4.110-gdac1439 #20 [ 29.218786] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.228112] 0000000000000000 7cc659d46a26c94e ffff8801d07878d0 ffffffff81d04e3d [ 29.236090] ffffea00074aa700 ffff8801d2a9c0b8 0000000000000000 ffff8801d2a9c0b8 [ 29.244094] 0000000000000000 ffff8801d0787908 ffffffff814fd1f3 ffff8801d2a9c0b8 [ 29.252068] Call Trace: [ 29.254625] [] dump_stack+0xc1/0x124 [ 29.259958] [] print_address_description+0x73/0x260 [ 29.266600] [] kasan_report+0x285/0x370 [ 29.272189] [] ? __lock_acquire+0x387e/0x4b50 [ 29.278307] [] __asan_report_load8_noabort+0x14/0x20 [ 29.285021] [] __lock_acquire+0x387e/0x4b50 [ 29.290963] [] ? __lock_acquire+0xb5f/0x4b50 [ 29.296988] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.303966] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.310952] [] ? mark_held_locks+0xaf/0x100 [ 29.316887] [] lock_acquire+0x15e/0x460 [ 29.322490] [] ? remove_wait_queue+0x14/0x40 [ 29.328527] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 29.334820] [] ? remove_wait_queue+0x14/0x40 [ 29.340844] [] remove_wait_queue+0x14/0x40 [ 29.346697] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 29.353675] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 29.360922] [] ? ep_free+0x1c0/0x1c0 [ 29.366252] [] ep_free+0x93/0x1c0 [ 29.371320] [] ? ep_free+0x1c0/0x1c0 [ 29.376650] [] ep_eventpoll_release+0x44/0x60 [ 29.382767] [] __fput+0x233/0x6d0 [ 29.387837] [] ____fput+0x15/0x20 [ 29.392906] [] task_work_run+0x104/0x180 [ 29.398589] [] do_exit+0x871/0x2a20 [ 29.403837] [] ? release_task+0x1240/0x1240 [ 29.409775] [] ? SyS_epoll_create+0x190/0x190 [ 29.415891] [] do_group_exit+0x108/0x320 [ 29.421572] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 29.428030] [] SyS_exit_group+0x1d/0x20 [ 29.433620] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.440162] [ 29.441756] Allocated by task 3325: [ 29.445352] [] save_stack_trace+0x26/0x50 [ 29.451247] [] save_stack+0x43/0xd0 [ 29.456605] [] kasan_kmalloc+0xad/0xe0 [ 29.462226] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.468800] [] binder_get_thread+0x181/0x7a0 [ 29.474938] [] binder_poll+0x4a/0x210 [ 29.480467] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.486430] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.493103] [ 29.494700] Freed by task 3325: [ 29.497949] [] save_stack_trace+0x26/0x50 [ 29.503827] [] save_stack+0x43/0xd0 [ 29.509199] [] kasan_slab_free+0x72/0xc0 [ 29.514998] [] kfree+0xfc/0x300 [ 29.520005] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.526747] [] binder_thread_release+0x27d/0x540 [ 29.533241] [] binder_ioctl+0xb94/0x12e0 [ 29.539029] [] do_vfs_ioctl+0x7aa/0xee0 [ 29.544732] [] SyS_ioctl+0x8f/0xc0 [ 29.549997] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.556653] [ 29.558247] The buggy address belongs to the object at ffff8801d2a9c000 [ 29.558247] which belongs to the cache kmalloc-512 of size 512 [ 29.570887] The buggy address is located 184 bytes inside of [ 29.570887] 512-byte region [ffff8801d2a9c000, ffff8801d2a9c200) [ 29.582729] The buggy address belongs to the page: [ 31.147915] PANIC: double fault, error_code: 0x0 [ 31.152693] CPU: 1 PID: 3325 Comm: syzkaller446647 Not tainted 4.4.110-gdac1439 #20 [ 31.160460] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.169781] task: ffff8800b47b97c0 task.stack: ffff8801d0780000 [ 31.175806] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 31.184656] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 31.190073] RAX: ffff8800b47b97c0 RBX: ffffea00074aa700 RCX: ffffffff8148f740 [ 31.197317] RDX: 0000000000000000 RSI: ffffffff838a8320 RDI: ffffea00074aa700 [ 31.204553] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 31.211804] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 31.219064] R13: ffffffff838a8320 R14: 0000000000000000 R15: 0000000000000000 [ 31.226305] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 31.234503] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 31.240358] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 31.247597] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 31.254833] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 31.262066] Stack: [ 31.264178] [ 31.265769] Call Trace: [ 31.268317] [ 31.270342] Code: e2 06 00 e9 1d fd ff ff 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb 48 83 ec 08 61 06 ed ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 31.296962] Kernel panic - not syncing: Machine halted. [ 31.302290] CPU: 1 PID: 3325 Comm: syzkaller446647 Not tainted 4.4.110-gdac1439 #20 [ 31.310047] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.319369] 0000000000000000 7cc659d46a26c94e ffff8801db30ce38 ffffffff81d04e3d [ 31.327313] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 31.335256] 0000000000000000 ffff8801db30cf00 ffffffff814197fa 0000000041b58ab3 [ 31.343202] Call Trace: [ 31.345749] <#DF> [] dump_stack+0xc1/0x124 [ 31.351816] [] panic+0x1aa/0x388 [ 31.356799] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 31.363693] [] ? vprintk_emit+0x242/0x850 [ 31.369459] [] ? dump_page_badflags+0x2f/0x250 [ 31.375656] [] ? vprintk_emit+0x242/0x850 [ 31.381419] [] df_debug+0x2d/0x30 [ 31.386487] [] do_double_fault+0x10b/0x210 [ 31.392336] [] double_fault+0x2d/0x40 [ 31.397752] [] ? dump_page_badflags+0x180/0x250 [ 31.404050] [] ? dump_page_badflags+0x1a/0x250 [ 31.410243] <> [ 31.413662] Dumping ftrace buffer: [ 31.417462] (ftrace buffer empty) [ 31.421139] Kernel Offset: disabled [ 31.424728] Rebooting in 86400 seconds..