[[0;32m OK [0m] Reached target Login Prompts. [[0;32m OK [0m] Reached target Multi-User System. [[0;32m OK [0m] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [[0;32m OK [0m] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.201' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 76.735113][ T26] audit: type=1400 audit(1601902041.113:8): avc: denied { execmem } for pid=6875 comm="syz-executor795" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 76.742325][ T6876] netlink: 32 bytes leftover after parsing attributes in process `syz-executor795'. [ 76.797609][ T6876] ================================================================== [ 76.805784][ T6876] BUG: KASAN: use-after-free in tcf_action_destroy+0x188/0x1b0 [ 76.813403][ T6876] Read of size 8 at addr ffff88809ee75400 by task syz-executor795/6876 [ 76.821623][ T6876] [ 76.823952][ T6876] CPU: 1 PID: 6876 Comm: syz-executor795 Not tainted 5.9.0-rc8-syzkaller #0 [ 76.832610][ T6876] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 76.842818][ T6876] Call Trace: [ 76.846110][ T6876] dump_stack+0x198/0x1fd [ 76.850424][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 76.855607][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 76.860814][ T6876] print_address_description.constprop.0.cold+0xae/0x497 [ 76.867819][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 76.873015][ T6876] ? lockdep_hardirqs_off+0x96/0xd0 [ 76.878215][ T6876] ? vprintk_func+0x95/0x1d4 [ 76.882791][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 76.887968][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 76.894373][ T6876] kasan_report.cold+0x1f/0x37 [ 76.899152][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 76.904332][ T6876] tcf_action_destroy+0x188/0x1b0 [ 76.909340][ T6876] tcf_action_init+0x29c/0x3d0 [ 76.914087][ T6876] ? tcf_action_init_1+0xac0/0xac0 [ 76.919196][ T6876] ? avc_has_perm_noaudit+0x1ee/0x390 [ 76.924548][ T6876] tcf_action_add+0xd9/0x360 [ 76.929135][ T6876] ? tca_action_gd+0xe20/0xe20 [ 76.933898][ T6876] ? bpf_lsm_capable+0x5/0x10 [ 76.938556][ T6876] ? __nla_parse+0x3d/0x4a [ 76.942972][ T6876] tc_ctl_action+0x33a/0x439 [ 76.947546][ T6876] ? tcf_action_add+0x360/0x360 [ 76.952383][ T6876] ? lock_is_held_type+0xbb/0xf0 [ 76.957305][ T6876] ? tcf_action_add+0x360/0x360 [ 76.962131][ T6876] rtnetlink_rcv_msg+0x44e/0xad0 [ 76.967050][ T6876] ? rtnetlink_put_metrics+0x510/0x510 [ 76.972488][ T6876] ? lock_acquire+0x1f3/0xaf0 [ 76.977144][ T6876] ? netlink_deliver_tap+0x146/0xb70 [ 76.982411][ T6876] netlink_rcv_skb+0x15a/0x430 [ 76.987159][ T6876] ? rtnetlink_put_metrics+0x510/0x510 [ 76.992614][ T6876] ? netlink_ack+0xa10/0xa10 [ 76.997196][ T6876] netlink_unicast+0x533/0x7d0 [ 77.001941][ T6876] ? netlink_attachskb+0x810/0x810 [ 77.007036][ T6876] netlink_sendmsg+0x856/0xd90 [ 77.011780][ T6876] ? netlink_unicast+0x7d0/0x7d0 [ 77.016789][ T6876] ? bpf_lsm_socket_sendmsg+0x5/0x10 [ 77.022056][ T6876] ? netlink_unicast+0x7d0/0x7d0 [ 77.026976][ T6876] sock_sendmsg+0xcf/0x120 [ 77.031373][ T6876] ____sys_sendmsg+0x6e8/0x810 [ 77.036130][ T6876] ? kernel_sendmsg+0x50/0x50 [ 77.040793][ T6876] ? do_recvmmsg+0x6d0/0x6d0 [ 77.045365][ T6876] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 77.051322][ T6876] ? lock_is_held_type+0xbb/0xf0 [ 77.056253][ T6876] ? find_held_lock+0x2d/0x110 [ 77.060996][ T6876] ___sys_sendmsg+0xf3/0x170 [ 77.065567][ T6876] ? sendmsg_copy_msghdr+0x160/0x160 [ 77.070844][ T6876] ? __fget_files+0x272/0x400 [ 77.075515][ T6876] ? lock_downgrade+0x830/0x830 [ 77.080349][ T6876] ? do_huge_pmd_anonymous_page+0x8f2/0x2200 [ 77.086321][ T6876] ? __fget_files+0x294/0x400 [ 77.090981][ T6876] ? __fget_light+0xea/0x280 [ 77.095568][ T6876] __sys_sendmsg+0xe5/0x1b0 [ 77.100063][ T6876] ? __sys_sendmsg_sock+0xb0/0xb0 [ 77.105075][ T6876] ? check_preemption_disabled+0x50/0x130 [ 77.110817][ T6876] ? syscall_enter_from_user_mode+0x1d/0x60 [ 77.116826][ T6876] do_syscall_64+0x2d/0x70 [ 77.121243][ T6876] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 77.127114][ T6876] RIP: 0033:0x445d79 [ 77.130988][ T6876] Code: e8 bc b7 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 ab 11 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 77.150587][ T6876] RSP: 002b:00007f6a74b28d98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 77.158979][ T6876] RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000445d79 [ 77.166931][ T6876] RDX: 0000000000000000 RSI: 0000000020002980 RDI: 0000000000000003 [ 77.174882][ T6876] RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 [ 77.182842][ T6876] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac2c [ 77.190796][ T6876] R13: 0001008400000000 R14: 0000000000000000 R15: 053b003000000098 [ 77.198763][ T6876] [ 77.201081][ T6876] Allocated by task 6876: [ 77.205391][ T6876] kasan_save_stack+0x1b/0x40 [ 77.210064][ T6876] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 77.215672][ T6876] __kmalloc+0x1b0/0x360 [ 77.219892][ T6876] tcf_idr_create+0x5b/0x800 [ 77.224457][ T6876] tcf_connmark_init+0x535/0x960 [ 77.229373][ T6876] tcf_action_init_1+0x6a5/0xac0 [ 77.234286][ T6876] tcf_action_init+0x260/0x3d0 [ 77.239026][ T6876] tcf_action_add+0xd9/0x360 [ 77.243594][ T6876] tc_ctl_action+0x33a/0x439 [ 77.248173][ T6876] rtnetlink_rcv_msg+0x44e/0xad0 [ 77.253087][ T6876] netlink_rcv_skb+0x15a/0x430 [ 77.257832][ T6876] netlink_unicast+0x533/0x7d0 [ 77.262572][ T6876] netlink_sendmsg+0x856/0xd90 [ 77.267313][ T6876] sock_sendmsg+0xcf/0x120 [ 77.271718][ T6876] ____sys_sendmsg+0x6e8/0x810 [ 77.276479][ T6876] ___sys_sendmsg+0xf3/0x170 [ 77.281046][ T6876] __sys_sendmsg+0xe5/0x1b0 [ 77.285528][ T6876] do_syscall_64+0x2d/0x70 [ 77.289964][ T6876] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 77.295859][ T6876] [ 77.298166][ T6876] Freed by task 6878: [ 77.302140][ T6876] kasan_save_stack+0x1b/0x40 [ 77.306809][ T6876] kasan_set_track+0x1c/0x30 [ 77.311464][ T6876] kasan_set_free_info+0x1b/0x30 [ 77.316397][ T6876] __kasan_slab_free+0xd8/0x120 [ 77.321223][ T6876] kfree+0x10e/0x2b0 [ 77.325101][ T6876] tcf_generic_walker+0x959/0xb60 [ 77.330104][ T6876] tca_action_flush+0x42b/0x920 [ 77.334930][ T6876] tca_action_gd+0x8c9/0xe20 [ 77.339498][ T6876] tc_ctl_action+0x280/0x439 [ 77.344081][ T6876] rtnetlink_rcv_msg+0x44e/0xad0 [ 77.348996][ T6876] netlink_rcv_skb+0x15a/0x430 [ 77.353750][ T6876] netlink_unicast+0x533/0x7d0 [ 77.358491][ T6876] netlink_sendmsg+0x856/0xd90 [ 77.363234][ T6876] sock_sendmsg+0xcf/0x120 [ 77.367642][ T6876] ____sys_sendmsg+0x6e8/0x810 [ 77.372396][ T6876] ___sys_sendmsg+0xf3/0x170 [ 77.376962][ T6876] __sys_sendmsg+0xe5/0x1b0 [ 77.381459][ T6876] do_syscall_64+0x2d/0x70 [ 77.385854][ T6876] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 77.391715][ T6876] [ 77.394030][ T6876] The buggy address belongs to the object at ffff88809ee75400 [ 77.394030][ T6876] which belongs to the cache kmalloc-512 of size 512 [ 77.408076][ T6876] The buggy address is located 0 bytes inside of [ 77.408076][ T6876] 512-byte region [ffff88809ee75400, ffff88809ee75600) [ 77.421162][ T6876] The buggy address belongs to the page: [ 77.426775][ T6876] page:000000004cb01f57 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9ee75 [ 77.436896][ T6876] flags: 0xfffe0000000200(slab) [ 77.441725][ T6876] raw: 00fffe0000000200 ffffea000287eec8 ffffea0002974108 ffff8880aa040600 [ 77.450305][ T6876] raw: 0000000000000000 ffff88809ee75000 0000000100000004 0000000000000000 [ 77.458878][ T6876] page dumped because: kasan: bad access detected [ 77.465301][ T6876] [ 77.467607][ T6876] Memory state around the buggy address: [ 77.473215][ T6876] ffff88809ee75300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 77.481253][ T6876] ffff88809ee75380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 77.489292][ T6876] >ffff88809ee75400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.497341][ T6876] ^ [ 77.501399][ T6876] ffff88809ee75480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.509436][ T6876] ffff88809ee75500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.517484][ T6876] ================================================================== [ 77.525518][ T6876] Disabling lock debugging due to kernel taint [ 77.545695][ T6876] Kernel panic - not syncing: panic_on_warn set ... [ 77.552309][ T6876] CPU: 1 PID: 6876 Comm: syz-executor795 Tainted: G B 5.9.0-rc8-syzkaller #0 [ 77.562359][ T6876] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 77.572494][ T6876] Call Trace: [ 77.575784][ T6876] dump_stack+0x198/0x1fd [ 77.580108][ T6876] ? tcf_action_destroy+0x130/0x1b0 [ 77.585296][ T6876] panic+0x382/0x7fb [ 77.589197][ T6876] ? __warn_printk+0xf3/0xf3 [ 77.593761][ T6876] ? preempt_schedule_common+0x59/0xc0 [ 77.599197][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 77.604370][ T6876] ? preempt_schedule_thunk+0x16/0x18 [ 77.609717][ T6876] ? trace_hardirqs_on+0x55/0x220 [ 77.614741][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 77.619917][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 77.625096][ T6876] end_report+0x4d/0x53 [ 77.629240][ T6876] kasan_report.cold+0xd/0x37 [ 77.633897][ T6876] ? tcf_action_destroy+0x188/0x1b0 [ 77.639070][ T6876] tcf_action_destroy+0x188/0x1b0 [ 77.644067][ T6876] tcf_action_init+0x29c/0x3d0 [ 77.648809][ T6876] ? tcf_action_init_1+0xac0/0xac0 [ 77.653902][ T6876] ? avc_has_perm_noaudit+0x1ee/0x390 [ 77.659250][ T6876] tcf_action_add+0xd9/0x360 [ 77.663818][ T6876] ? tca_action_gd+0xe20/0xe20 [ 77.668596][ T6876] ? bpf_lsm_capable+0x5/0x10 [ 77.673246][ T6876] ? __nla_parse+0x3d/0x4a [ 77.677636][ T6876] tc_ctl_action+0x33a/0x439 [ 77.682202][ T6876] ? tcf_action_add+0x360/0x360 [ 77.687029][ T6876] ? lock_is_held_type+0xbb/0xf0 [ 77.691948][ T6876] ? tcf_action_add+0x360/0x360 [ 77.696773][ T6876] rtnetlink_rcv_msg+0x44e/0xad0 [ 77.701687][ T6876] ? rtnetlink_put_metrics+0x510/0x510 [ 77.707136][ T6876] ? lock_acquire+0x1f3/0xaf0 [ 77.711790][ T6876] ? netlink_deliver_tap+0x146/0xb70 [ 77.717057][ T6876] netlink_rcv_skb+0x15a/0x430 [ 77.721813][ T6876] ? rtnetlink_put_metrics+0x510/0x510 [ 77.727246][ T6876] ? netlink_ack+0xa10/0xa10 [ 77.731810][ T6876] netlink_unicast+0x533/0x7d0 [ 77.736547][ T6876] ? netlink_attachskb+0x810/0x810 [ 77.741631][ T6876] netlink_sendmsg+0x856/0xd90 [ 77.746388][ T6876] ? netlink_unicast+0x7d0/0x7d0 [ 77.751300][ T6876] ? bpf_lsm_socket_sendmsg+0x5/0x10 [ 77.756572][ T6876] ? netlink_unicast+0x7d0/0x7d0 [ 77.761497][ T6876] sock_sendmsg+0xcf/0x120 [ 77.765891][ T6876] ____sys_sendmsg+0x6e8/0x810 [ 77.770628][ T6876] ? kernel_sendmsg+0x50/0x50 [ 77.775287][ T6876] ? do_recvmmsg+0x6d0/0x6d0 [ 77.779855][ T6876] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 77.785822][ T6876] ? lock_is_held_type+0xbb/0xf0 [ 77.790733][ T6876] ? find_held_lock+0x2d/0x110 [ 77.795471][ T6876] ___sys_sendmsg+0xf3/0x170 [ 77.800048][ T6876] ? sendmsg_copy_msghdr+0x160/0x160 [ 77.805480][ T6876] ? __fget_files+0x272/0x400 [ 77.810135][ T6876] ? lock_downgrade+0x830/0x830 [ 77.814962][ T6876] ? do_huge_pmd_anonymous_page+0x8f2/0x2200 [ 77.820914][ T6876] ? __fget_files+0x294/0x400 [ 77.825571][ T6876] ? __fget_light+0xea/0x280 [ 77.830150][ T6876] __sys_sendmsg+0xe5/0x1b0 [ 77.834626][ T6876] ? __sys_sendmsg_sock+0xb0/0xb0 [ 77.839628][ T6876] ? check_preemption_disabled+0x50/0x130 [ 77.845333][ T6876] ? syscall_enter_from_user_mode+0x1d/0x60 [ 77.851200][ T6876] do_syscall_64+0x2d/0x70 [ 77.855589][ T6876] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 77.861452][ T6876] RIP: 0033:0x445d79 [ 77.865323][ T6876] Code: e8 bc b7 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 ab 11 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 77.884905][ T6876] RSP: 002b:00007f6a74b28d98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 77.893297][ T6876] RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000445d79 [ 77.901241][ T6876] RDX: 0000000000000000 RSI: 0000000020002980 RDI: 0000000000000003 [ 77.909198][ T6876] RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 [ 77.917143][ T6876] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac2c [ 77.925097][ T6876] R13: 0001008400000000 R14: 0000000000000000 R15: 053b003000000098 [ 77.934169][ T6876] Kernel Offset: disabled [ 77.938483][ T6876] Rebooting in 86400 seconds..