[ 16.025695] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.511886] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.973126] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.879225] random: sshd: uninitialized urandom read (32 bytes read, 112 bits of entropy available) [ 23.051831] random: sshd: uninitialized urandom read (32 bytes read, 117 bits of entropy available) Warning: Permanently added '10.128.15.212' (ECDSA) to the list of known hosts. [ 28.432649] random: sshd: uninitialized urandom read (32 bytes read, 125 bits of entropy available) executing program [ 28.529334] ================================================================== [ 28.536725] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.543388] Read of size 8 at addr ffff8801d3f86d38 by task syzkaller031076/3325 [ 28.550889] [ 28.552492] CPU: 0 PID: 3325 Comm: syzkaller031076 Not tainted 4.4.112-g3fc4284 #25 [ 28.560262] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.569593] 0000000000000000 e92c0bfb57d1234d ffff8801d00e7850 ffffffff81d054ed [ 28.577561] ffffea00074fe180 ffff8801d3f86d38 0000000000000000 ffff8801d3f86d38 [ 28.585527] 0000000000000000 ffff8801d00e7888 ffffffff814fd953 ffff8801d3f86d38 [ 28.593494] Call Trace: [ 28.596054] [] dump_stack+0xc1/0x124 [ 28.601389] [] print_address_description+0x73/0x260 [ 28.608025] [] kasan_report+0x285/0x370 [ 28.613623] [] ? __lock_acquire+0x387e/0x4b50 [ 28.619737] [] __asan_report_load8_noabort+0x14/0x20 [ 28.626458] [] __lock_acquire+0x387e/0x4b50 [ 28.632406] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.638436] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.645436] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 28.652250] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.659236] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.666229] [] lock_acquire+0x15e/0x460 [ 28.671824] [] ? remove_wait_queue+0x14/0x40 [ 28.677854] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.684145] [] ? remove_wait_queue+0x14/0x40 [ 28.690185] [] remove_wait_queue+0x14/0x40 [ 28.696043] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.703036] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.710280] [] ? ep_free+0x1c0/0x1c0 [ 28.715612] [] ep_free+0x93/0x1c0 [ 28.720684] [] ? ep_free+0x1c0/0x1c0 [ 28.726015] [] ep_eventpoll_release+0x44/0x60 [ 28.732134] [] __fput+0x233/0x6d0 [ 28.737207] [] ____fput+0x15/0x20 [ 28.742283] [] task_work_run+0x104/0x180 [ 28.747960] [] do_exit+0x871/0x2a20 [ 28.753209] [] ? handle_mm_fault+0x192d/0x3190 [ 28.759412] [] ? handle_mm_fault+0x3f2/0x3190 [ 28.765542] [] ? release_task+0x1240/0x1240 [ 28.771486] [] do_group_exit+0x108/0x320 [ 28.777168] [] SyS_exit_group+0x1d/0x20 [ 28.782766] [] ? do_group_exit+0x320/0x320 [ 28.788634] [] do_fast_syscall_32+0x314/0x890 [ 28.794757] [] sysenter_flags_fixed+0xd/0x17 [ 28.800781] [ 28.802379] Allocated by task 3325: [ 28.805970] [] save_stack_trace+0x26/0x50 [ 28.811875] [] save_stack+0x43/0xd0 [ 28.817243] [] kasan_kmalloc+0xad/0xe0 [ 28.822869] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 28.829450] [] binder_get_thread+0x181/0x7a0 [ 28.835597] [] binder_poll+0x4a/0x210 [ 28.841148] [] SyS_epoll_ctl+0x10b1/0x2050 [ 28.847124] [] do_fast_syscall_32+0x314/0x890 [ 28.853375] [] sysenter_flags_fixed+0xd/0x17 [ 28.859533] [ 28.861130] Freed by task 3325: [ 28.864377] [] save_stack_trace+0x26/0x50 [ 28.870263] [] save_stack+0x43/0xd0 [ 28.875635] [] kasan_slab_free+0x72/0xc0 [ 28.881432] [] kfree+0xfc/0x300 [ 28.886453] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.893233] [] binder_thread_release+0x27d/0x540 [ 28.899747] [] binder_ioctl+0xb94/0x12e0 [ 28.905550] [] compat_SyS_ioctl+0x28a/0x2540 [ 28.911721] [] do_fast_syscall_32+0x314/0x890 [ 28.917964] [] sysenter_flags_fixed+0xd/0x17 [ 28.924122] [ 28.925720] The buggy address belongs to the object at ffff8801d3f86c80 [ 28.925720] which belongs to the cache kmalloc-512 of size 512 [ 28.938351] The buggy address is located 184 bytes inside of [ 28.938351] 512-byte region [ffff8801d3f86c80, ffff8801d3f86e80) [ 28.950211] The buggy address belongs to the page: [ 30.577812] PANIC: double fault, error_code: 0x0 [ 30.582610] CPU: 0 PID: 3325 Comm: syzkaller031076 Not tainted 4.4.112-g3fc4284 #25 [ 30.590378] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.599714] task: ffff8800b4478000 task.stack: ffff8801d00e0000 [ 30.605751] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 30.614593] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 30.620012] RAX: ffff8800b4478000 RBX: ffffea00074fe180 RCX: ffffffff8148fea0 [ 30.627250] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea00074fe180 [ 30.634501] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 30.641754] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 30.648996] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 30.656243] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 30.664442] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 30.670298] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.677548] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.684792] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.692045] Stack: [ 30.694162] [ 30.695756] Call Trace: [ 30.698320] [ 30.700349] 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 [ 30.727263] Kernel panic - not syncing: Machine halted. [ 30.732606] CPU: 0 PID: 3325 Comm: syzkaller031076 Not tainted 4.4.112-g3fc4284 #25 [ 30.740382] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.749720] 0000000000000000 e92c0bfb57d1234d ffff8801db20ce38 ffffffff81d054ed [ 30.757714] ffffffff83836a60 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 30.765680] 0000000000000000 ffff8801db20cf00 ffffffff81419dca 0000000041b58ab3 [ 30.773672] Call Trace: [ 30.776229] <#DF> [] dump_stack+0xc1/0x124 [ 30.782309] [] panic+0x1aa/0x388 [ 30.787295] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.794196] [] ? vprintk_emit+0x242/0x850 [ 30.799970] [] ? dump_page_badflags+0x2f/0x250 [ 30.806174] [] ? vprintk_emit+0x242/0x850 [ 30.811943] [] df_debug+0x2d/0x30 [ 30.817026] [] do_double_fault+0x10b/0x210 [ 30.822908] [] double_fault+0x2d/0x40 [ 30.828341] [] ? dump_page_badflags+0x180/0x250 [ 30.834630] [] ? dump_page_badflags+0x1a/0x250 [ 30.840858] <> [ 30.844253] Dumping ftrace buffer: [ 30.848063] (ftrace buffer empty) [ 30.851745] Kernel Offset: disabled [ 30.855341] Rebooting in 86400 seconds..