[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 57.258479] audit: type=1800 audit(1542254673.311:25): pid=6517 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 57.277767] audit: type=1800 audit(1542254673.311:26): pid=6517 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 57.297236] audit: type=1800 audit(1542254673.341:27): pid=6517 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.16' (ECDSA) to the list of known hosts. syzkaller login: [ 67.646413] IPVS: ftp: loaded support on port[0] = 21 executing program executing program [ 67.732229] L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. executing program executing program executing program executing program executing program executing program executing program executing program [ 68.100941] ================================================================== [ 68.108371] BUG: KMSAN: kernel-infoleak in _copy_to_user+0x19a/0x230 [ 68.114874] CPU: 0 PID: 6697 Comm: syz-executor853 Not tainted 4.20.0-rc2+ #85 [ 68.122224] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.131571] Call Trace: [ 68.134159] dump_stack+0x32d/0x480 [ 68.137937] ? _copy_to_user+0x19a/0x230 [ 68.142009] kmsan_report+0x19f/0x300 [ 68.145815] kmsan_internal_check_memory+0x35b/0x3b0 [ 68.150921] kmsan_copy_to_user+0x7c/0xe0 [ 68.155075] _copy_to_user+0x19a/0x230 [ 68.158977] kvm_arch_vcpu_ioctl+0x5dee/0x7680 [ 68.163572] ? kmsan_internal_unpoison_shadow+0x83/0xd0 [ 68.168955] kvm_vcpu_ioctl+0xca3/0x1f90 [ 68.173051] ? do_vfs_ioctl+0x184/0x2f70 [ 68.177115] ? __se_sys_ioctl+0x1da/0x270 [ 68.181299] ? kvm_vm_release+0x90/0x90 [ 68.185267] do_vfs_ioctl+0xfbc/0x2f70 [ 68.189153] ? security_file_ioctl+0x92/0x200 [ 68.193644] __se_sys_ioctl+0x1da/0x270 [ 68.197612] __x64_sys_ioctl+0x4a/0x70 [ 68.201536] do_syscall_64+0xcf/0x110 [ 68.205333] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 68.210511] RIP: 0033:0x4471b9 [ 68.213708] Code: e8 fc b9 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 68.232899] RSP: 002b:00007f1e22946da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 68.240601] RAX: ffffffffffffffda RBX: 00000000006f0038 RCX: 00000000004471b9 [ 68.247863] RDX: 0000000020000000 RSI: 000000004068aea3 RDI: 0000000000000005 [ 68.255127] RBP: 00000000006f0030 R08: 0000000000000000 R09: 0000000000000000 [ 68.262390] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006f003c [ 68.269649] R13: 6d766b2f7665642f R14: 00007f1e229479c0 R15: 00000000000003e8 [ 68.276930] [ 68.278558] Local variable description: ----__pu_val@kvm_arch_vcpu_ioctl [ 68.285379] Variable was created at: [ 68.289093] kvm_arch_vcpu_ioctl+0x29d/0x7680 [ 68.293579] kvm_vcpu_ioctl+0xca3/0x1f90 [ 68.297621] [ 68.299259] Bytes 0-1 of 2 are uninitialized [ 68.303655] Memory access of size 2 starts at ffff8881967ffbb0 [ 68.309618] Data copied to user address 0000000000706000 [ 68.315072] ================================================================== [ 68.322415] Disabling lock debugging due to kernel taint [ 68.327851] Kernel panic - not syncing: panic_on_warn set ... [ 68.333748] CPU: 0 PID: 6697 Comm: syz-executor853 Tainted: G B 4.20.0-rc2+ #85 [ 68.342516] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.351861] Call Trace: [ 68.354445] dump_stack+0x32d/0x480 [ 68.358082] panic+0x624/0xc08 [ 68.361283] kmsan_report+0x300/0x300 [ 68.365088] kmsan_internal_check_memory+0x35b/0x3b0 [ 68.370196] kmsan_copy_to_user+0x7c/0xe0 [ 68.374338] _copy_to_user+0x19a/0x230 [ 68.378224] kvm_arch_vcpu_ioctl+0x5dee/0x7680 [ 68.382802] ? kmsan_internal_unpoison_shadow+0x83/0xd0 [ 68.388174] kvm_vcpu_ioctl+0xca3/0x1f90 [ 68.392237] ? do_vfs_ioctl+0x184/0x2f70 [ 68.396307] ? __se_sys_ioctl+0x1da/0x270 [ 68.400449] ? kvm_vm_release+0x90/0x90 [ 68.404413] do_vfs_ioctl+0xfbc/0x2f70 [ 68.408304] ? security_file_ioctl+0x92/0x200 [ 68.412792] __se_sys_ioctl+0x1da/0x270 [ 68.416762] __x64_sys_ioctl+0x4a/0x70 [ 68.420655] do_syscall_64+0xcf/0x110 [ 68.424599] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 68.429780] RIP: 0033:0x4471b9 [ 68.432965] Code: e8 fc b9 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 68.451857] RSP: 002b:00007f1e22946da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 68.459554] RAX: ffffffffffffffda RBX: 00000000006f0038 RCX: 00000000004471b9 [ 68.466814] RDX: 0000000020000000 RSI: 000000004068aea3 RDI: 0000000000000005 [ 68.474078] RBP: 00000000006f0030 R08: 0000000000000000 R09: 0000000000000000 [ 68.481346] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006f003c [ 68.488611] R13: 6d766b2f7665642f R14: 00007f1e229479c0 R15: 00000000000003e8 [ 68.497362] Kernel Offset: disabled [ 68.500998] Rebooting in 86400 seconds..