[ 13.536765] random: sshd: uninitialized urandom read (32 bytes read, 31 bits of entropy available) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 17.308904] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 17.628328] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 18.457663] random: sshd: uninitialized urandom read (32 bytes read, 104 bits of entropy available) [ 18.613189] random: sshd: uninitialized urandom read (32 bytes read, 108 bits of entropy available) Warning: Permanently added 'ci-android-44-kasan-gce-386-2,10.128.15.238' (ECDSA) to the list of known hosts. [ 24.005064] random: sshd: uninitialized urandom read (32 bytes read, 113 bits of entropy available) executing program [ 24.099972] ================================================================== [ 24.107367] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 24.113998] Read of size 8 at addr ffff8800b4561c38 by task syzkaller926737/3303 [ 24.121494] [ 24.123087] CPU: 0 PID: 3303 Comm: syzkaller926737 Not tainted 4.4.106-g1700518 #1 [ 24.130755] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.140084] 0000000000000000 face907d7a8d95c7 ffff8801d17af850 ffffffff81d02f7d [ 24.148029] ffffea0002d15800 ffff8800b4561c38 0000000000000000 ffff8800b4561c38 [ 24.155967] 0000000000000000 ffff8801d17af888 ffffffff814fa843 ffff8800b4561c38 [ 24.163911] Call Trace: [ 24.166463] [] dump_stack+0xc1/0x124 [ 24.171792] [] print_address_description+0x73/0x260 [ 24.178421] [] kasan_report+0x285/0x370 [ 24.184011] [] ? __lock_acquire+0x387e/0x4b50 [ 24.190117] [] __asan_report_load8_noabort+0x14/0x20 [ 24.196832] [] __lock_acquire+0x387e/0x4b50 [ 24.202767] [] ? __lock_acquire+0xb5f/0x4b50 [ 24.208788] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 24.215765] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 24.222568] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 24.229545] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 24.236519] [] lock_acquire+0x15e/0x460 [ 24.242107] [] ? remove_wait_queue+0x14/0x40 [ 24.248129] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 24.254411] [] ? remove_wait_queue+0x14/0x40 [ 24.260432] [] remove_wait_queue+0x14/0x40 [ 24.266281] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 24.273257] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 24.280493] [] ? ep_free+0x1c0/0x1c0 [ 24.285820] [] ep_free+0x93/0x1c0 [ 24.290887] [] ? ep_free+0x1c0/0x1c0 [ 24.296215] [] ep_eventpoll_release+0x44/0x60 [ 24.302324] [] __fput+0x233/0x6d0 [ 24.307393] [] ____fput+0x15/0x20 [ 24.312460] [] task_work_run+0x104/0x180 [ 24.318137] [] do_exit+0x871/0x2a20 [ 24.323379] [] ? handle_mm_fault+0x192d/0x3190 [ 24.329573] [] ? handle_mm_fault+0x3f2/0x3190 [ 24.335679] [] ? release_task+0x1240/0x1240 [ 24.341613] [] do_group_exit+0x108/0x320 [ 24.347287] [] SyS_exit_group+0x1d/0x20 [ 24.352872] [] ? do_group_exit+0x320/0x320 [ 24.358718] [] do_fast_syscall_32+0x314/0x890 [ 24.364827] [] sysenter_flags_fixed+0xd/0x17 [ 24.370845] [ 24.372440] Allocated by task 3303: [ 24.376027] [] save_stack_trace+0x26/0x50 [ 24.381900] [] save_stack+0x43/0xd0 [ 24.387251] [] kasan_kmalloc+0xad/0xe0 [ 24.392862] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 24.399427] [] binder_get_thread+0x181/0x7a0 [ 24.405559] [] binder_poll+0x4a/0x210 [ 24.411081] [] SyS_epoll_ctl+0x10b1/0x2050 [ 24.417042] [] do_fast_syscall_32+0x314/0x890 [ 24.423264] [] sysenter_flags_fixed+0xd/0x17 [ 24.429398] [ 24.430992] Freed by task 3303: [ 24.434237] [] save_stack_trace+0x26/0x50 [ 24.440112] [] save_stack+0x43/0xd0 [ 24.445466] [] kasan_slab_free+0x72/0xc0 [ 24.451249] [] kfree+0xe9/0x2f0 [ 24.456252] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 24.462993] [] binder_thread_release+0x27d/0x540 [ 24.469476] [] binder_ioctl+0xb94/0x12e0 [ 24.475269] [] compat_SyS_ioctl+0x28a/0x2540 [ 24.481406] [] do_fast_syscall_32+0x314/0x890 [ 24.487626] [] sysenter_flags_fixed+0xd/0x17 [ 24.493757] [ 24.495348] The buggy address belongs to the object at ffff8800b4561b80 [ 24.495348] which belongs to the cache kmalloc-512 of size 512 [ 24.507966] The buggy address is located 184 bytes inside of [ 24.507966] 512-byte region [ffff8800b4561b80, ffff8800b4561d80) [ 24.519802] The buggy address belongs to the page: [ 25.976602] PANIC: double fault, error_code: 0x0 [ 25.981374] CPU: 0 PID: 3303 Comm: syzkaller926737 Not tainted 4.4.106-g1700518 #1 [ 25.989044] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.998363] task: ffff8801d18497c0 task.stack: ffff8801d17a8000 [ 26.004381] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 26.013213] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 26.018625] RAX: ffff8801d18497c0 RBX: ffffea0002d15800 RCX: ffffffff8148d2d0 [ 26.025859] RDX: 0000000000000000 RSI: ffffffff838a7e20 RDI: ffffea0002d15800 [ 26.033093] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 26.040331] R10: 0000000000000002 R11: fffffbfff0ad581e R12: 0000000000000000 [ 26.047564] R13: ffffffff838a7e20 R14: 0000000000000000 R15: 0000000000000000 [ 26.054800] FS: 0000000000000000(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000 [ 26.062993] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 26.068840] CR2: ffff8800fffffff8 CR3: 000000000420b000 CR4: 00000000001406f0 [ 26.076076] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 26.083311] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 26.090541] Stack: [ 26.092653] [ 26.094244] Call Trace: [ 26.096801] [ 26.098824] Code: dd 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 51 f8 ec ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 26.125386] Kernel panic - not syncing: Machine halted. [ 26.130714] CPU: 0 PID: 3303 Comm: syzkaller926737 Not tainted 4.4.106-g1700518 #1 [ 26.138382] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.147700] 0000000000000000 face907d7a8d95c7 ffff8801db409e38 ffffffff81d02f7d [ 26.155639] ffffffff83836620 ffff8801db409f10 ffffffff83808040 ffff880100000000 [ 26.163580] 0000000000000000 ffff8801db409f00 ffffffff8141654a 0000000041b58ab3 [ 26.171517] Call Trace: [ 26.174062] <#DF> [] dump_stack+0xc1/0x124 [ 26.180119] [] panic+0x1aa/0x388 [ 26.185099] [] ? percpu_up_read.constprop.46+0xe1/0xe1 [ 26.191988] [] ? vprintk_emit+0x242/0x850 [ 26.197747] [] ? dump_page_badflags+0x2f/0x250 [ 26.203940] [] ? vprintk_emit+0x242/0x850 [ 26.209702] [] df_debug+0x2d/0x30 [ 26.214770] [] do_double_fault+0x10b/0x210 [ 26.220618] [] double_fault+0x2d/0x40 [ 26.226031] [] ? dump_page_badflags+0x180/0x250 [ 26.232311] [] ? dump_page_badflags+0x1a/0x250 [ 26.238501] <> [ 26.241785] Dumping ftrace buffer: [ 26.245574] (ftrace buffer empty) [ 26.249246] Kernel Offset: disabled [ 26.252835] Rebooting in 86400 seconds..