[ 15.894505] 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: [ 21.155096] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.560105] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.330781] random: sshd: uninitialized urandom read (32 bytes read, 84 bits of entropy available) [ 45.298107] random: sshd: uninitialized urandom read (32 bytes read, 95 bits of entropy available) Warning: Permanently added '10.128.0.27' (ECDSA) to the list of known hosts. [ 50.676823] random: sshd: uninitialized urandom read (32 bytes read, 101 bits of entropy available) executing program [ 50.768121] ================================================================== [ 50.775508] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0xf9/0x110 [ 50.782492] Read of size 8 at addr ffff8801d1bda140 by task syzkaller210785/3324 [ 50.789992] [ 50.791595] CPU: 0 PID: 3324 Comm: syzkaller210785 Not tainted 4.4.113-ge70c132 #34 [ 50.799371] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.808706] 0000000000000000 bfe6495c8f134624 ffff8801d06e79f0 ffffffff81d0278d [ 50.816681] ffffea000746f680 ffff8801d1bda140 0000000000000000 ffff8801d1bda140 [ 50.824648] ffff8801d0674438 ffff8801d06e7a28 ffffffff814fd053 ffff8801d1bda140 [ 50.832620] Call Trace: [ 50.835193] [] dump_stack+0xc1/0x124 [ 50.840527] [] print_address_description+0x73/0x260 [ 50.847165] [] kasan_report+0x285/0x370 [ 50.852758] [] ? sg_remove_request+0xf9/0x110 [ 50.858871] [] __asan_report_load8_noabort+0x14/0x20 [ 50.865592] [] sg_remove_request+0xf9/0x110 [ 50.871531] [] sg_finish_rem_req+0x295/0x340 [ 50.877558] [] sg_read+0xa1b/0x1490 [ 50.882811] [] ? __check_object_size+0x154/0x35b [ 50.889185] [] ? sg_proc_seq_show_debug+0xda0/0xda0 [ 50.895821] [] ? fsnotify+0xee0/0xee0 [ 50.901242] [] ? avc_policy_seqno+0x9/0x20 [ 50.907106] [] do_loop_readv_writev+0x141/0x1e0 [ 50.913394] [] ? security_file_permission+0x89/0x1e0 [ 50.920118] [] ? sg_proc_seq_show_debug+0xda0/0xda0 [ 50.926756] [] ? sg_proc_seq_show_debug+0xda0/0xda0 [ 50.933395] [] do_readv_writev+0x5dd/0x6e0 [ 50.939249] [] ? vfs_write+0x530/0x530 [ 50.944756] [] ? handle_mm_fault+0xbf5/0x3190 [ 50.950869] [] ? _raw_spin_unlock+0x2c/0x50 [ 50.956811] [] ? handle_mm_fault+0x3f2/0x3190 [ 50.962925] [] ? fasync_insert_entry+0x147/0x2e0 [ 50.969300] [] vfs_readv+0x78/0xb0 [ 50.974461] [] SyS_readv+0xd9/0x240 [ 50.979707] [] ? rw_copy_check_uvector+0x2b0/0x2b0 [ 50.986257] [] ? trace_hardirqs_on_thunk+0x17/0x19 [ 50.992803] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 50.999347] [ 51.000949] Allocated by task 0: [ 51.004281] (stack is not available) [ 51.007961] [ 51.009556] Freed by task 0: [ 51.012540] (stack is not available) [ 51.016220] [ 51.017818] The buggy address belongs to the object at ffff8801d1bda100 [ 51.017818] which belongs to the cache fasync_cache of size 96 [ 51.030442] The buggy address is located 64 bytes inside of [ 51.030442] 96-byte region [ffff8801d1bda100, ffff8801d1bda160) [ 51.042121] The buggy address belongs to the page: [ 51.261532] kasan: CONFIG_KASAN_INLINE enabled [ 51.265976] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 51.278794] Dumping ftrace buffer: [ 51.282301] (ftrace buffer empty) [ 51.285979] Modules linked in: [ 51.289261] CPU: 1 PID: 490 Comm: khugepaged Not tainted 4.4.113-ge70c132 #34 [ 51.296499] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.305822] task: ffff8800bb2c2f80 task.stack: ffff8801d9308000 [ 51.311845] RIP: 0010:[] [] __lock_acquire+0x61f/0x4b50 [ 51.320528] RSP: 0018:ffff8801d930fa20 EFLAGS: 00010002 [ 51.325946] RAX: dffffc0000000000 RBX: 0428bb8d48ffed02 RCX: 0000000000000000 [ 51.333187] RDX: 1ffffffff0291f3d RSI: 0000000000000001 RDI: ffffffff8148f9e9 [ 51.340427] RBP: ffff8801d930fbb8 R08: 0000000000000001 R09: 0000000000000000 [ 51.347665] R10: 0000000000000001 R11: 1ffff1003b261f56 R12: 0000000000000000 [ 51.354905] R13: ffff8800bb2c2f80 R14: ffffffff8148f9e1 R15: 0000000000000000 [ 51.362144] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 51.370341] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 51.376196] CR2: 000055d04a7fb100 CR3: 00000001d1214000 CR4: 0000000000160670 [ 51.383453] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 51.390693] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 51.397932] Stack: [ 51.400048] ffffffff857f0d88 ffff8801d930fa48 ffffffff85175180 ffff8800bb2c3808 [ 51.408012] ffff8800bb2c37e0 ffff8800bb2c37e8 ffff8800bb2c3810 ffff8800004352ca [ 51.415977] 0000000000000200 0000000000055fe0 ffffffff85174fd0 ffff8800bb2c3808 [ 51.423959] Call Trace: [ 51.426519] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 51.433503] [] ? __alloc_pages_direct_compact+0x250/0x250 [ 51.440657] [] ? prepare_to_wait_event+0x114/0x420 [ 51.447203] [] lock_acquire+0x15e/0x460 [ 51.452796] [] ? khugepaged+0x7fe/0x28a0 [ 51.458475] [] ? dump_page_badflags+0x231/0x250 [ 51.464766] [] down_read+0x42/0x60 [ 51.469925] [] ? khugepaged+0x7fe/0x28a0 [ 51.475604] [] ? dump_page_badflags+0x191/0x250 [ 51.481893] [] khugepaged+0x7fe/0x28a0 [ 51.487399] [] ? dump_page_badflags+0x231/0x250 [ 51.493685] [] ? dump_page_badflags+0x191/0x250 [ 51.499972] [] ? set_huge_zero_page.isra.52.part.53+0x100/0x100 [ 51.507648] [] ? prepare_to_wait_event+0x420/0x420 [ 51.514197] [] ? __kthread_parkme+0x167/0x230 [ 51.520309] [] kthread+0x268/0x300 [ 51.525466] [] ? set_huge_zero_page.isra.52.part.53+0x100/0x100 [ 51.533143] [] ? kthread_create_on_node+0x400/0x400 [ 51.539780] [] ? kthread_create_on_node+0x400/0x400 [ 51.546415] [] ret_from_fork+0x55/0x80 [ 51.551921] [] ? kthread_create_on_node+0x400/0x400 [ 51.558553] Code: 00 fc ff df 44 89 e3 49 8d 7c de 08 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b6 37 00 00 49 8b 5c de 08 48 85 db 0f 84 28 fb ff ff ff 83 98 01 00 00 49 8d 85 68 08 00 00 48 89 c2 48 89 44 24 [ 51.585112] RIP [] __lock_acquire+0x61f/0x4b50 [ 51.591432] RSP [ 51.595028] ---[ end trace 8ad8064e66e9e32e ]--- [ 51.599750] Kernel panic - not syncing: Fatal exception [ 52.583278] PANIC: double fault, error_code: 0x0 [ 52.588054] CPU: 0 PID: 3324 Comm: syzkaller210785 Tainted: G D 4.4.113-ge70c132 #34 [ 52.597203] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.606527] task: ffff8801d1bb2f80 task.stack: ffff8801d06e0000 [ 52.612562] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 52.621312] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 52.626730] RAX: ffff8801d1bb2f80 RBX: ffffea000746f680 RCX: ffffffff8148f8d0 [ 52.633967] RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea000746f680 [ 52.641204] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 52.648443] R10: 0000000000000002 R11: fffffbfff0ad7e26 R12: 0000000000000000 [ 52.655696] R13: ffffffff838a8de0 R14: 0000000000000000 R15: 0000000000000000