[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 12.664685] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 14.492942] random: sshd: uninitialized urandom read (32 bytes read) [ 14.712689] random: sshd: uninitialized urandom read (32 bytes read) [ 15.203582] random: sshd: uninitialized urandom read (32 bytes read) [ 18.176434] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.15.210' (ECDSA) to the list of known hosts. [ 23.604345] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.840569] ================================================================== [ 23.848110] BUG: KASAN: stack-out-of-bounds in __unwind_start+0x37c/0x3c0 [ 23.855081] Read of size 8 at addr ffff8801d977fc88 by task syz-executor972/3912 [ 23.862661] [ 23.864271] CPU: 0 PID: 3912 Comm: syz-executor972 Not tainted 4.9.118-g47b77b8 #72 [ 23.872042] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.881372] ffff8801d962f140 ffffffff81eb4b89 ffffea000765dfc0 ffff8801d977fc88 [ 23.889352] 0000000000000000 ffff8801d977fc88 ffff8801d962f278 ffff8801d962f178 [ 23.897327] ffffffff81567f29 ffff8801d977fc88 0000000000000008 0000000000000000 [ 23.905394] Call Trace: [ 23.908108] [] dump_stack+0xc1/0x128 [ 23.913449] [] print_address_description+0x6c/0x234 [ 23.920101] [] kasan_report.cold.6+0x242/0x2fe [ 23.926312] [] ? __unwind_start+0x37c/0x3c0 [ 23.932369] [] __asan_report_load8_noabort+0x14/0x20 [ 23.939098] [] __unwind_start+0x37c/0x3c0 [ 23.944868] [] ? ptrace_may_access+0x24/0x50 [ 23.950903] [] __save_stack_trace+0x59/0xf0 [ 23.956849] [] save_stack_trace_tsk+0x48/0x70 [ 23.962974] [] proc_pid_stack+0x148/0x220 [ 23.968749] [] ? lock_trace+0xc0/0xc0 [ 23.974178] [] proc_single_show+0xfd/0x170 [ 23.980036] [] seq_read+0x4b6/0x12e0 [ 23.985369] [] ? seq_dentry+0x290/0x290 [ 23.990975] [] ? __fsnotify_update_child_dentry_flags.part.1+0x300/0x300 [ 23.999454] [] ? fsnotify+0x1100/0x1100 [ 24.005058] [] do_loop_readv_writev.part.18+0xd5/0x280 [ 24.011956] [] do_readv_writev+0x565/0x7a0 [ 24.017811] [] ? vfs_write+0x530/0x530 [ 24.023322] [] ? kasan_unpoison_shadow+0x35/0x50 [ 24.029703] [] ? push_pipe+0x3f4/0x780 [ 24.035218] [] ? iov_iter_get_pages_alloc+0x2bb/0xf10 [ 24.042037] [] vfs_readv+0x84/0xc0 [ 24.047219] [] default_file_splice_read+0x44b/0x7e0 [ 24.053863] [] ? depot_save_stack+0x132/0x460 [ 24.059988] [] ? do_splice_direct+0x270/0x270 [ 24.066113] [] ? save_stack_trace+0x16/0x20 [ 24.072061] [] ? kasan_kmalloc+0xc7/0xe0 [ 24.077753] [] ? __kmalloc+0x11d/0x300 [ 24.083267] [] ? alloc_pipe_info+0x164/0x380 [ 24.089380] [] ? splice_direct_to_actor+0x62c/0x7e0 [ 24.096028] [] ? do_splice_direct+0x1a3/0x270 [ 24.102146] [] ? do_sendfile+0x4f0/0xc60 [ 24.107830] [] ? SyS_sendfile64+0xd1/0x160 [ 24.113688] [] ? entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.120776] [] ? refill_pi_state_cache.part.8+0x200/0x200 [ 24.127940] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 24.134757] [] ? security_file_permission+0x8f/0x1f0 [ 24.141487] [] ? do_splice_direct+0x270/0x270 [ 24.147710] [] do_splice_to+0x10c/0x170 [ 24.153319] [] splice_direct_to_actor+0x23f/0x7e0 [ 24.159787] [] ? pipe_to_sendpage+0x330/0x330 [ 24.165923] [] ? do_splice_to+0x170/0x170 [ 24.171699] [] ? security_file_permission+0x8f/0x1f0 [ 24.178431] [] ? rw_verify_area+0xe5/0x2b0 [ 24.184289] [] do_splice_direct+0x1a3/0x270 [ 24.190236] [] ? splice_direct_to_actor+0x7e0/0x7e0 [ 24.196939] [] ? rcu_sync_lockdep_assert+0x73/0xb0 [ 24.203498] [] ? __sb_start_write+0x161/0x300 [ 24.209624] [] do_sendfile+0x4f0/0xc60 [ 24.215137] [] ? do_compat_pwritev64+0x180/0x180 [ 24.221518] [] ? __might_fault+0x114/0x1d0 [ 24.227507] [] SyS_sendfile64+0xd1/0x160 [ 24.233196] [] ? SyS_sendfile+0x160/0x160 [ 24.238988] [] ? do_syscall_64+0x48/0x490 [ 24.244769] [] ? SyS_sendfile+0x160/0x160 [ 24.250542] [] do_syscall_64+0x1a6/0x490 [ 24.256228] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.263132] [ 24.264736] The buggy address belongs to the page: [ 24.269641] page:ffffea000765dfc0 count:0 mapcount:0 mapping: (null) index:0x0 [ 24.277879] flags: 0x8000000000000000() [ 24.281824] page dumped because: kasan: bad access detected [ 24.287557] [ 24.289163] Memory state around the buggy address: [ 24.294136] ffff8801d977fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 24.301474] ffff8801d977fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 24.308816] >ffff8801d977fc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 24.316201] ^ [ 24.319807] ffff8801d977fd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 24.327140] ffff8801d977fd80: 00 00 f1 f1 f1 f1 00 f2 f2 f2 f2 f2 f2 f2 00 f2 [ 24.334520] ================================================================== [ 24.341854] Disabling lock debugging due to kernel taint [ 24.348103] Kernel panic - not syncing: panic_on_warn set ... [ 24.348103] [ 24.355508] CPU: 0 PID: 3912 Comm: syz-executor972 Tainted: G B 4.9.118-g47b77b8 #72 [ 24.364493] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.373823] ffff8801d962f0a0 ffffffff81eb4b89 ffffffff843c8907 00000000ffffffff [ 24.381805] 0000000000000000 0000000000000000 ffff8801d962f278 ffff8801d962f160 [ 24.389782] ffffffff81421c25 0000000041b58ab3 ffffffff843bbfe8 ffffffff81421a66 [ 24.397779] Call Trace: [ 24.400344] [] dump_stack+0xc1/0x128 [ 24.405686] [] panic+0x1bf/0x3bc [ 24.410789] [] ? add_taint.cold.6+0x16/0x16 [ 24.416742] [] ? ___preempt_schedule+0x16/0x18 [ 24.423039] [] kasan_end_report+0x47/0x4f [ 24.428814] [] kasan_report.cold.6+0x76/0x2fe [ 24.434945] [] ? __unwind_start+0x37c/0x3c0 [ 24.440896] [] __asan_report_load8_noabort+0x14/0x20 [ 24.447631] [] __unwind_start+0x37c/0x3c0 [ 24.453407] [] ? ptrace_may_access+0x24/0x50 [ 24.459450] [] __save_stack_trace+0x59/0xf0 [ 24.465398] [] save_stack_trace_tsk+0x48/0x70 [ 24.471520] [] proc_pid_stack+0x148/0x220 [ 24.477290] [] ? lock_trace+0xc0/0xc0 [ 24.482716] [] proc_single_show+0xfd/0x170 [ 24.488578] [] seq_read+0x4b6/0x12e0 [ 24.493922] [] ? seq_dentry+0x290/0x290 [ 24.499531] [] ? __fsnotify_update_child_dentry_flags.part.1+0x300/0x300 [ 24.508003] [] ? fsnotify+0x1100/0x1100 [ 24.513605] [] do_loop_readv_writev.part.18+0xd5/0x280 [ 24.520510] [] do_readv_writev+0x565/0x7a0 [ 24.526372] [] ? vfs_write+0x530/0x530 [ 24.531885] [] ? kasan_unpoison_shadow+0x35/0x50 [ 24.538269] [] ? push_pipe+0x3f4/0x780 [ 24.543785] [] ? iov_iter_get_pages_alloc+0x2bb/0xf10 [ 24.550610] [] vfs_readv+0x84/0xc0 [ 24.555878] [] default_file_splice_read+0x44b/0x7e0 [ 24.562532] [] ? depot_save_stack+0x132/0x460 [ 24.568652] [] ? do_splice_direct+0x270/0x270 [ 24.574773] [] ? save_stack_trace+0x16/0x20 [ 24.580715] [] ? kasan_kmalloc+0xc7/0xe0 [ 24.586537] [] ? __kmalloc+0x11d/0x300 [ 24.592048] [] ? alloc_pipe_info+0x164/0x380 [ 24.598075] [] ? splice_direct_to_actor+0x62c/0x7e0 [ 24.604721] [] ? do_splice_direct+0x1a3/0x270 [ 24.611082] [] ? do_sendfile+0x4f0/0xc60 [ 24.616762] [] ? SyS_sendfile64+0xd1/0x160 [ 24.622617] [] ? entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.629688] [] ? refill_pi_state_cache.part.8+0x200/0x200 [ 24.636843] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 24.643655] [] ? security_file_permission+0x8f/0x1f0 [ 24.650377] [] ? do_splice_direct+0x270/0x270 [ 24.656489] [] do_splice_to+0x10c/0x170 [ 24.662085] [] splice_direct_to_actor+0x23f/0x7e0 [ 24.668547] [] ? pipe_to_sendpage+0x330/0x330 [ 24.674664] [] ? do_splice_to+0x170/0x170 [ 24.680433] [] ? security_file_permission+0x8f/0x1f0 [ 24.687162] [] ? rw_verify_area+0xe5/0x2b0 [ 24.693020] [] do_splice_direct+0x1a3/0x270 [ 24.699007] [] ? splice_direct_to_actor+0x7e0/0x7e0 [ 24.705642] [] ? rcu_sync_lockdep_assert+0x73/0xb0 [ 24.712196] [] ? __sb_start_write+0x161/0x300 [ 24.718313] [] do_sendfile+0x4f0/0xc60 [ 24.723834] [] ? do_compat_pwritev64+0x180/0x180 [ 24.730214] [] ? __might_fault+0x114/0x1d0 [ 24.736071] [] SyS_sendfile64+0xd1/0x160 [ 24.741759] [] ? SyS_sendfile+0x160/0x160 [ 24.747535] [] ? do_syscall_64+0x48/0x490 [ 24.753311] [] ? SyS_sendfile+0x160/0x160 [ 24.759081] [] do_syscall_64+0x1a6/0x490 [ 24.764763] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.772162] Dumping ftrace buffer: [ 24.775819] (ftrace buffer empty) [ 24.779502] Kernel Offset: disabled [ 24.783098] Rebooting in 86400 seconds..