[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 15.663827] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.553732] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.945070] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.879920] random: sshd: uninitialized urandom read (32 bytes read, 114 bits of entropy available) [ 23.050458] random: sshd: uninitialized urandom read (32 bytes read, 120 bits of entropy available) Warning: Permanently added '10.128.15.217' (ECDSA) to the list of known hosts. [ 28.405212] random: nonblocking pool is initialized executing program [ 28.514026] ================================================================== [ 28.521420] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.528060] Read of size 8 at addr ffff8801d10c74b8 by task syzkaller352093/3313 [ 28.535559] [ 28.537156] CPU: 1 PID: 3313 Comm: syzkaller352093 Not tainted 4.4.112-g3fc4284 #32 [ 28.544913] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.554234] 0000000000000000 7423d876623a52be ffff8801d1b578d0 ffffffff81d054ed [ 28.562197] ffffea0007443180 ffff8801d10c74b8 0000000000000000 ffff8801d10c74b8 [ 28.570150] 0000000000000000 ffff8801d1b57908 ffffffff814fd953 ffff8801d10c74b8 [ 28.578104] Call Trace: [ 28.580661] [] dump_stack+0xc1/0x124 [ 28.585993] [] print_address_description+0x73/0x260 [ 28.592639] [] kasan_report+0x285/0x370 [ 28.598244] [] ? __lock_acquire+0x387e/0x4b50 [ 28.604359] [] __asan_report_load8_noabort+0x14/0x20 [ 28.611079] [] __lock_acquire+0x387e/0x4b50 [ 28.617018] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.623042] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.630023] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.637029] [] ? mark_held_locks+0xaf/0x100 [ 28.642966] [] lock_acquire+0x15e/0x460 [ 28.648561] [] ? remove_wait_queue+0x14/0x40 [ 28.654589] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.660878] [] ? remove_wait_queue+0x14/0x40 [ 28.666904] [] remove_wait_queue+0x14/0x40 [ 28.672756] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.679736] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.686978] [] ? ep_free+0x1c0/0x1c0 [ 28.692308] [] ep_free+0x93/0x1c0 [ 28.697378] [] ? ep_free+0x1c0/0x1c0 [ 28.702707] [] ep_eventpoll_release+0x44/0x60 [ 28.708818] [] __fput+0x233/0x6d0 [ 28.713889] [] ____fput+0x15/0x20 [ 28.718971] [] task_work_run+0x104/0x180 [ 28.724654] [] do_exit+0x871/0x2a20 [ 28.729900] [] ? release_task+0x1240/0x1240 [ 28.735840] [] ? SyS_epoll_create+0x190/0x190 [ 28.741954] [] do_group_exit+0x108/0x320 [ 28.747643] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 28.754105] [] SyS_exit_group+0x1d/0x20 [ 28.759698] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 28.766240] [ 28.767836] Allocated by task 3313: [ 28.771425] [] save_stack_trace+0x26/0x50 [ 28.777309] [] save_stack+0x43/0xd0 [ 28.782667] [] kasan_kmalloc+0xad/0xe0 [ 28.788294] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 28.794865] [] binder_get_thread+0x181/0x7a0 [ 28.801011] [] binder_poll+0x4a/0x210 [ 28.806551] [] SyS_epoll_ctl+0x10b1/0x2050 [ 28.812523] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 28.819188] [ 28.820785] Freed by task 3313: [ 28.824030] [] save_stack_trace+0x26/0x50 [ 28.829911] [] save_stack+0x43/0xd0 [ 28.835269] [] kasan_slab_free+0x72/0xc0 [ 28.841062] [] kfree+0xfc/0x300 [ 28.846075] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.852823] [] binder_thread_release+0x27d/0x540 [ 28.859316] [] binder_ioctl+0xb94/0x12e0 [ 28.865114] [] do_vfs_ioctl+0x7aa/0xee0 [ 28.870827] [] SyS_ioctl+0x8f/0xc0 [ 28.876096] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 28.882757] [ 28.884355] The buggy address belongs to the object at ffff8801d10c7400 [ 28.884355] which belongs to the cache kmalloc-512 of size 512 [ 28.896988] The buggy address is located 184 bytes inside of [ 28.896988] 512-byte region [ffff8801d10c7400, ffff8801d10c7600) [ 28.908827] The buggy address belongs to the page: [ 30.322341] PANIC: double fault, error_code: 0x0 [ 30.327109] CPU: 1 PID: 0 Comm: €1D Not tainted 4.4.112-g3fc4284 #32 [ 30.333654] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.343458] task: ffff8801d1888000 task.stack: ffffea0007443180 [ 30.349495] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 30.358336] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 30.363754] RAX: ffff8801d1888000 RBX: ffffea0007443180 RCX: ffffffff8148fea0 [ 30.370994] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea0007443180 [ 30.378233] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 30.385472] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 30.392709] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 30.399950] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 30.408144] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 30.414000] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.421241] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.428478] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.435723] Stack: [ 30.437839] [ 30.439431] Call Trace: [ 30.441980] [ 30.444007] 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 11 01 ed ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 30.470869] Kernel panic - not syncing: Machine halted. [ 30.476202] CPU: 1 PID: 0 Comm: €1D Not tainted 4.4.112-g3fc4284 #32 [ 30.482746] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.492069] 0000000000000000 7423d876623a52be ffff8801db30ce38 ffffffff81d054ed [ 30.500042] ffffffff83836a60 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 30.508001] 0000000000000000 ffff8801db30cf00 ffffffff81419dca 0000000041b58ab3 [ 30.515970] Call Trace: [ 30.518520] <#DF> [] dump_stack+0xc1/0x124 [ 30.524583] [] panic+0x1aa/0x388 [ 30.529568] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.536461] [] ? vprintk_emit+0x242/0x850 [ 30.542224] [] ? dump_page_badflags+0x2f/0x250 [ 30.548422] [] ? vprintk_emit+0x242/0x850 [ 30.554186] [] df_debug+0x2d/0x30 [ 30.559260] [] do_double_fault+0x10b/0x210 [ 30.565110] [] double_fault+0x2d/0x40 [ 30.570529] [] ? dump_page_badflags+0x180/0x250 [ 30.576820] [] ? dump_page_badflags+0x1a/0x250 [ 30.583016] <> [ 30.586456] Dumping ftrace buffer: [ 30.590300] (ftrace buffer empty) [ 30.593981] Kernel Offset: disabled [ 30.597596] Rebooting in 86400 seconds..