[ 16.949123] 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: [ 19.785861] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 20.074426] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 21.036400] random: sshd: uninitialized urandom read (32 bytes read, 115 bits of entropy available) [ 21.249599] random: sshd: uninitialized urandom read (32 bytes read, 120 bits of entropy available) Warning: Permanently added '10.128.15.235' (ECDSA) to the list of known hosts. [ 26.624860] random: sshd: uninitialized urandom read (32 bytes read, 126 bits of entropy available) executing program [ 26.726937] ================================================================== [ 26.734336] BUG: KASAN: slab-out-of-bounds in sg_remove_request+0xf9/0x110 [ 26.741334] Read of size 8 at addr ffff8801d129d140 by task syzkaller607658/3316 [ 26.748848] [ 26.750452] CPU: 1 PID: 3316 Comm: syzkaller607658 Not tainted 4.4.111-g1849cd3 #19 [ 26.758215] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.767545] 0000000000000000 08b5108fcdfc1d42 ffff8801d0cef970 ffffffff81d0509d [ 26.775529] ffffea000744a740 ffff8801d129d140 0000000000000000 ffff8801d129d140 [ 26.783519] ffff8801d0454438 ffff8801d0cef9a8 ffffffff814fd433 ffff8801d129d140 [ 26.791494] Call Trace: [ 26.794059] [] dump_stack+0xc1/0x124 [ 26.799401] [] print_address_description+0x73/0x260 [ 26.806042] [] kasan_report+0x285/0x370 [ 26.811657] [] ? sg_remove_request+0xf9/0x110 [ 26.817789] [] __asan_report_load8_noabort+0x14/0x20 [ 26.824516] [] sg_remove_request+0xf9/0x110 [ 26.830458] [] sg_finish_rem_req+0x295/0x340 [ 26.836490] [] sg_read+0xa21/0x1490 [ 26.841746] [] ? do_page_fault+0x27/0x30 [ 26.847434] [] ? page_fault+0x28/0x30 [ 26.852861] [] ? sg_proc_seq_show_debug+0xd30/0xd30 [ 26.859499] [] ? fsnotify+0xee0/0xee0 [ 26.864926] [] ? avc_policy_seqno+0x9/0x20 [ 26.870786] [] do_loop_readv_writev+0x141/0x1e0 [ 26.877082] [] ? security_file_permission+0x89/0x1e0 [ 26.883820] [] ? sg_proc_seq_show_debug+0xd30/0xd30 [ 26.890462] [] ? sg_proc_seq_show_debug+0xd30/0xd30 [ 26.897109] [] compat_do_readv_writev+0x5df/0x6e0 [ 26.903575] [] ? vfs_writev+0xb0/0xb0 [ 26.909011] [] ? _raw_spin_unlock+0x2c/0x50 [ 26.914958] [] ? handle_mm_fault+0x3f2/0x3190 [ 26.921077] [] ? putname+0xee/0x130 [ 26.926332] [] ? rcu_read_lock_sched_held+0x103/0x120 [ 26.933149] [] ? kmem_cache_free+0x2a4/0x320 [ 26.939187] [] compat_readv+0xd9/0x140 [ 26.944704] [] compat_SyS_readv+0xd8/0x1b0 [ 26.950562] [] ? SyS_pwritev+0x230/0x230 [ 26.956248] [] ? do_fast_syscall_32+0xd7/0x890 [ 26.962452] [] ? SyS_pwritev+0x230/0x230 [ 26.968138] [] do_fast_syscall_32+0x314/0x890 [ 26.974264] [] sysenter_flags_fixed+0xd/0x17 [ 26.980293] [ 26.981909] Allocated by task 0: [ 26.985243] (stack is not available) [ 26.988923] [ 26.990520] Freed by task 0: [ 26.993505] (stack is not available) [ 26.997194] [ 26.998801] The buggy address belongs to the object at ffff8801d129d100 [ 26.998801] which belongs to the cache fasync_cache of size 96 [ 27.011436] The buggy address is located 64 bytes inside of [ 27.011436] 96-byte region [ffff8801d129d100, ffff8801d129d160) [ 27.023111] The buggy address belongs to the page: [ 27.179913] kasan: CONFIG_KASAN_INLINE enabled [ 27.184377] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 27.197388] Dumping ftrace buffer: [ 27.200939] (ftrace buffer empty) [ 27.204674] Modules linked in: [ 27.208036] CPU: 0 PID: 3294 Comm: getty Not tainted 4.4.111-g1849cd3 #19 [ 27.214969] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.224337] task: ffff8800b647af80 task.stack: ffff8800b66f0000 [ 27.230403] RIP: 0010:[] [] debug_check_no_obj_freed+0x1a8/0x9b0 [ 27.239937] RSP: 0018:ffff8800b66f7b60 EFLAGS: 00010007 [ 27.245394] RAX: 0000000000000292 RBX: ffff8801d2c47590 RCX: 0000000000000003 [ 27.252678] RDX: 09ebe8eaa84be9aa RSI: ffff8800b66f7bf0 RDI: ffffffff838a8378 [ 27.259959] RBP: ffff8800b66f7c58 R08: 1ffffffff071506f R09: ffffffff8512a880 [ 27.267242] R10: dead000000000200 R11: 1ffff10016cdef32 R12: 0000292965676170 [ 27.274525] R13: ffff8801d2c474d8 R14: 4f5f4755425f4d56 R15: dffffc0000000000 [ 27.281904] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 27.290141] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.296037] CR2: 000055d4c0d59110 CR3: 000000000420c000 CR4: 0000000000160670 [ 27.303329] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 27.310611] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 27.317895] Stack: [ 27.320050] 0000000000000079 ffff8800b66f7bf0 0000000000000003 0000000000000292 [ 27.328129] 1ffff10016cdef7a ffffffff857a3b00 ffff8801d2c48000 ffff8801d2c47590 [ 27.336206] dead000000000200 4f5f4755425f4d56 00000000000450c0 fffffbfff0af4760 [ 27.344300] Call Trace: [ 27.346928] [] ? debug_object_active_state+0x420/0x420 [ 27.353879] [] ? kmem_cache_free+0x9d/0x320 [ 27.359879] [] ? put_io_context+0x112/0x150 [ 27.365877] [] ? put_io_context+0x112/0x150 [ 27.371876] [] kmem_cache_free+0xbc/0x320 [ 27.377699] [] put_io_context+0x112/0x150 [ 27.383522] [] put_io_context_active+0x294/0x370 [ 27.389951] [] exit_io_context+0x66/0x80 [ 27.395688] [] do_exit+0x13c0/0x2a20 [ 27.401106] [] ? debug_object_free+0x202/0x3a0 [ 27.407435] [] ? release_task+0x1240/0x1240 [ 27.413433] [] ? clock_was_set_work+0x30/0x30 [ 27.419607] [] ? do_nanosleep+0x19c/0x4f0 [ 27.425442] [] do_group_exit+0x108/0x320 [ 27.431174] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.437699] [] SyS_exit_group+0x1d/0x20 [ 27.443347] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.449960] Code: 48 c7 c6 40 ea 75 85 4c 8b 34 0e 4d 85 f6 0f 84 c5 03 00 00 49 ba 00 02 00 00 00 00 ad de 31 c9 48 8d 75 98 4c 89 f2 48 c1 ea 03 <42> 80 3c 3a 00 0f 85 f0 03 00 00 49 8d 7e 18 83 c1 01 49 8b 16 [ 27.477766] RIP [] debug_check_no_obj_freed+0x1a8/0x9b0 [ 27.484936] RSP [ 27.488570] ---[ end trace b6aeae0e1e6f5764 ]--- [ 27.493332] Kernel panic - not syncing: Fatal exception [ 28.626360] Shutting down cpus with NMI [ 28.630865] Dumping ftrace buffer: [ 28.634396] (ftrace buffer empty) [ 28.638077] Kernel Offset: disabled [ 28.641679] Rebooting in 86400 seconds..