[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 56.807560][ T23] audit: type=1800 audit(1570423569.732:25): pid=8713 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 56.849461][ T23] audit: type=1800 audit(1570423569.732:26): pid=8713 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 56.882980][ T23] audit: type=1800 audit(1570423569.732:27): pid=8713 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 '10.128.0.174' (ECDSA) to the list of known hosts. 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 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 67.912424][ T8990] ================================================================== [ 67.920698][ T8990] BUG: KASAN: use-after-free in tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 67.928876][ T8990] Read of size 2 at addr ffff888090c0f2d4 by task syz-executor616/8990 [ 67.937108][ T8990] [ 67.939451][ T8990] CPU: 1 PID: 8990 Comm: syz-executor616 Not tainted 5.4.0-rc1+ #0 [ 67.947334][ T8990] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.957386][ T8990] Call Trace: [ 67.960674][ T8990] dump_stack+0x172/0x1f0 [ 67.965145][ T8990] ? tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 67.970975][ T8990] print_address_description.constprop.0.cold+0xd4/0x30b [ 67.978020][ T8990] ? tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 67.984347][ T8990] ? tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 67.990137][ T8990] __kasan_report.cold+0x1b/0x41 [ 67.995070][ T8990] ? tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 68.000882][ T8990] kasan_report+0x12/0x20 [ 68.005217][ T8990] __asan_report_load2_noabort+0x14/0x20 [ 68.010840][ T8990] tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 68.016459][ T8990] ? mutex_trylock+0x2d0/0x2d0 [ 68.021206][ T8990] ? __kmalloc_node_track_caller+0x4e/0x70 [ 68.026998][ T8990] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 68.033237][ T8990] ? tipc_udp_enable+0x1380/0x1380 [ 68.038347][ T8990] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 68.044768][ T8990] ? __alloc_skb+0x3d0/0x5e0 [ 68.049468][ T8990] genl_lock_dumpit+0x86/0xc0 [ 68.054253][ T8990] netlink_dump+0x558/0xfb0 [ 68.058744][ T8990] ? netlink_broadcast+0x50/0x50 [ 68.063764][ T8990] __netlink_dump_start+0x5b1/0x7d0 [ 68.068945][ T8990] ? genl_lock_dumpit+0xc0/0xc0 [ 68.073829][ T8990] genl_rcv_msg+0xc9b/0x1000 [ 68.078411][ T8990] ? genl_family_rcv_msg_attrs_parse.isra.0+0x3a0/0x3a0 [ 68.086996][ T8990] ? genl_lock_dumpit+0xc0/0xc0 [ 68.091838][ T8990] ? genl_unlock+0x20/0x20 [ 68.096249][ T8990] ? genl_parallel_done+0x1c0/0x1c0 [ 68.101437][ T8990] ? mark_held_locks+0xf0/0xf0 [ 68.106185][ T8990] ? find_held_lock+0x35/0x130 [ 68.110938][ T8990] netlink_rcv_skb+0x177/0x450 [ 68.115687][ T8990] ? genl_family_rcv_msg_attrs_parse.isra.0+0x3a0/0x3a0 [ 68.122639][ T8990] ? netlink_ack+0xb50/0xb50 [ 68.127348][ T8990] ? __kasan_check_write+0x14/0x20 [ 68.132449][ T8990] ? netlink_deliver_tap+0x254/0xbf0 [ 68.137722][ T8990] genl_rcv+0x29/0x40 [ 68.141693][ T8990] netlink_unicast+0x531/0x710 [ 68.146444][ T8990] ? netlink_attachskb+0x7c0/0x7c0 [ 68.151543][ T8990] ? _copy_from_iter_full+0x25d/0x8c0 [ 68.156920][ T8990] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 68.162624][ T8990] ? __check_object_size+0x3d/0x437 [ 68.167812][ T8990] netlink_sendmsg+0x8a5/0xd60 [ 68.172580][ T8990] ? netlink_unicast+0x710/0x710 [ 68.177510][ T8990] ? aa_sock_msg_perm.isra.0+0xba/0x170 [ 68.183050][ T8990] ? apparmor_socket_sendmsg+0x2a/0x30 [ 68.188499][ T8990] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 68.194748][ T8990] ? security_socket_sendmsg+0x8d/0xc0 [ 68.200491][ T8990] ? netlink_unicast+0x710/0x710 [ 68.205502][ T8990] sock_sendmsg+0xd7/0x130 [ 68.209903][ T8990] ___sys_sendmsg+0x803/0x920 [ 68.214655][ T8990] ? copy_msghdr_from_user+0x440/0x440 [ 68.220127][ T8990] ? lock_downgrade+0x920/0x920 [ 68.224964][ T8990] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 68.230752][ T8990] ? lockdep_hardirqs_on+0x421/0x5e0 [ 68.236022][ T8990] ? __kasan_check_read+0x11/0x20 [ 68.241052][ T8990] ? mark_lock+0xc2/0x1220 [ 68.245469][ T8990] ? _raw_spin_unlock_irqrestore+0xa4/0xe0 [ 68.251271][ T8990] ? __kasan_check_read+0x11/0x20 [ 68.256277][ T8990] ? __lock_acquire+0x16f2/0x4a00 [ 68.261288][ T8990] ? debug_object_deactivate+0x320/0x320 [ 68.266909][ T8990] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 68.273069][ T8990] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 68.279331][ T8990] ? __fget_light+0x1a9/0x230 [ 68.283998][ T8990] ? __fdget+0x1b/0x20 [ 68.288071][ T8990] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 68.294304][ T8990] __sys_sendmsg+0x105/0x1d0 [ 68.298879][ T8990] ? __sys_sendmsg_sock+0xd0/0xd0 [ 68.303898][ T8990] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 68.309869][ T8990] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 68.315312][ T8990] ? do_syscall_64+0x26/0x760 [ 68.319984][ T8990] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 68.326040][ T8990] ? do_syscall_64+0x26/0x760 [ 68.330729][ T8990] __x64_sys_sendmsg+0x78/0xb0 [ 68.335488][ T8990] do_syscall_64+0xfa/0x760 [ 68.339990][ T8990] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 68.347177][ T8990] RIP: 0033:0x445279 [ 68.351070][ T8990] Code: e8 ac e8 ff ff 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 0b cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 68.370838][ T8990] RSP: 002b:00007fffac1fc178 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 68.379234][ T8990] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445279 [ 68.387193][ T8990] RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000005 [ 68.395167][ T8990] RBP: 0000000000010907 R08: 0000000000000000 R09: 00000000004002e0 [ 68.404601][ T8990] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402410 [ 68.412644][ T8990] R13: 00000000004024a0 R14: 0000000000000000 R15: 0000000000000000 [ 68.420621][ T8990] [ 68.422949][ T8990] Allocated by task 8992: [ 68.427285][ T8990] save_stack+0x23/0x90 [ 68.431435][ T8990] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 68.437052][ T8990] kasan_kmalloc+0x9/0x10 [ 68.441362][ T8990] __kmalloc_node_track_caller+0x4e/0x70 [ 68.446977][ T8990] __kmalloc_reserve.isra.0+0x40/0xf0 [ 68.452364][ T8990] __alloc_skb+0x10b/0x5e0 [ 68.456779][ T8990] netlink_sendmsg+0x972/0xd60 [ 68.461528][ T8990] sock_sendmsg+0xd7/0x130 [ 68.465922][ T8990] ___sys_sendmsg+0x803/0x920 [ 68.470596][ T8990] __sys_sendmsg+0x105/0x1d0 [ 68.475300][ T8990] __x64_sys_sendmsg+0x78/0xb0 [ 68.480059][ T8990] do_syscall_64+0xfa/0x760 [ 68.484550][ T8990] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 68.490425][ T8990] [ 68.492742][ T8990] Freed by task 8992: [ 68.496720][ T8990] save_stack+0x23/0x90 [ 68.500987][ T8990] __kasan_slab_free+0x102/0x150 [ 68.506713][ T8990] kasan_slab_free+0xe/0x10 [ 68.511208][ T8990] kfree+0x10a/0x2c0 [ 68.515095][ T8990] skb_free_head+0x93/0xb0 [ 68.519503][ T8990] skb_release_data+0x42d/0x7c0 [ 68.524353][ T8990] skb_release_all+0x4d/0x60 [ 68.528941][ T8990] consume_skb+0xfb/0x3b0 [ 68.533313][ T8990] netlink_unicast+0x539/0x710 [ 68.538070][ T8990] netlink_sendmsg+0x8a5/0xd60 [ 68.542824][ T8990] sock_sendmsg+0xd7/0x130 [ 68.547285][ T8990] ___sys_sendmsg+0x803/0x920 [ 68.551940][ T8990] __sys_sendmsg+0x105/0x1d0 [ 68.556509][ T8990] __x64_sys_sendmsg+0x78/0xb0 [ 68.561263][ T8990] do_syscall_64+0xfa/0x760 [ 68.565757][ T8990] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 68.571638][ T8990] [ 68.573962][ T8990] The buggy address belongs to the object at ffff888090c0f2c0 [ 68.573962][ T8990] which belongs to the cache kmalloc-512 of size 512 [ 68.588000][ T8990] The buggy address is located 20 bytes inside of [ 68.588000][ T8990] 512-byte region [ffff888090c0f2c0, ffff888090c0f4c0) [ 68.601171][ T8990] The buggy address belongs to the page: [ 68.606817][ T8990] page:ffffea00024303c0 refcount:1 mapcount:0 mapping:ffff8880aa400a80 index:0xffff888090c0fa40 [ 68.617228][ T8990] flags: 0x1fffc0000000200(slab) [ 68.622161][ T8990] raw: 01fffc0000000200 ffffea0002441548 ffffea0002430608 ffff8880aa400a80 [ 68.630739][ T8990] raw: ffff888090c0fa40 ffff888090c0f040 0000000100000005 0000000000000000 [ 68.639306][ T8990] page dumped because: kasan: bad access detected [ 68.645704][ T8990] [ 68.648022][ T8990] Memory state around the buggy address: [ 68.653636][ T8990] ffff888090c0f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program [ 68.661702][ T8990] ffff888090c0f200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 68.669747][ T8990] >ffff888090c0f280: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 68.677787][ T8990] ^ [ 68.684442][ T8990] ffff888090c0f300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 68.692502][ T8990] ffff888090c0f380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 68.700544][ T8990] ================================================================== [ 68.708594][ T8990] Disabling lock debugging due to kernel taint [ 68.717857][ T8990] Kernel panic - not syncing: panic_on_warn set ... [ 68.724469][ T8990] CPU: 1 PID: 8990 Comm: syz-executor616 Tainted: G B 5.4.0-rc1+ #0 [ 68.733730][ T8990] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.743770][ T8990] Call Trace: [ 68.747061][ T8990] dump_stack+0x172/0x1f0 [ 68.751383][ T8990] panic+0x2dc/0x755 [ 68.755256][ T8990] ? add_taint.cold+0x16/0x16 [ 68.760015][ T8990] ? tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 68.765816][ T8990] ? preempt_schedule+0x4b/0x60 [ 68.770662][ T8990] ? ___preempt_schedule+0x16/0x20 [ 68.775759][ T8990] ? trace_hardirqs_on+0x5e/0x240 [ 68.780771][ T8990] ? tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 68.786562][ T8990] end_report+0x47/0x4f [ 68.790698][ T8990] ? tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 68.796483][ T8990] __kasan_report.cold+0xe/0x41 [ 68.801326][ T8990] ? tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 68.807110][ T8990] kasan_report+0x12/0x20 [ 68.811418][ T8990] __asan_report_load2_noabort+0x14/0x20 [ 68.817034][ T8990] tipc_udp_nl_dump_remoteip+0xc19/0xc20 [ 68.822678][ T8990] ? mutex_trylock+0x2d0/0x2d0 [ 68.827422][ T8990] ? __kmalloc_node_track_caller+0x4e/0x70 [ 68.833208][ T8990] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 68.839450][ T8990] ? tipc_udp_enable+0x1380/0x1380 [ 68.844556][ T8990] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 68.850789][ T8990] ? __alloc_skb+0x3d0/0x5e0 [ 68.855372][ T8990] genl_lock_dumpit+0x86/0xc0 [ 68.860214][ T8990] netlink_dump+0x558/0xfb0 [ 68.864702][ T8990] ? netlink_broadcast+0x50/0x50 [ 68.870058][ T8990] __netlink_dump_start+0x5b1/0x7d0 [ 68.876200][ T8990] ? genl_lock_dumpit+0xc0/0xc0 [ 68.881052][ T8990] genl_rcv_msg+0xc9b/0x1000 [ 68.885635][ T8990] ? genl_family_rcv_msg_attrs_parse.isra.0+0x3a0/0x3a0 [ 68.893439][ T8990] ? genl_lock_dumpit+0xc0/0xc0 [ 68.898277][ T8990] ? genl_unlock+0x20/0x20 [ 68.902686][ T8990] ? genl_parallel_done+0x1c0/0x1c0 [ 68.907869][ T8990] ? mark_held_locks+0xf0/0xf0 [ 68.912716][ T8990] ? find_held_lock+0x35/0x130 [ 68.917469][ T8990] netlink_rcv_skb+0x177/0x450 [ 68.922215][ T8990] ? genl_family_rcv_msg_attrs_parse.isra.0+0x3a0/0x3a0 [ 68.929244][ T8990] ? netlink_ack+0xb50/0xb50 [ 68.933826][ T8990] ? __kasan_check_write+0x14/0x20 [ 68.938929][ T8990] ? netlink_deliver_tap+0x254/0xbf0 [ 68.944195][ T8990] genl_rcv+0x29/0x40 [ 68.948159][ T8990] netlink_unicast+0x531/0x710 [ 68.952911][ T8990] ? netlink_attachskb+0x7c0/0x7c0 [ 68.958019][ T8990] ? _copy_from_iter_full+0x25d/0x8c0 [ 68.963547][ T8990] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 68.969263][ T8990] ? __check_object_size+0x3d/0x437 [ 68.974448][ T8990] netlink_sendmsg+0x8a5/0xd60 [ 68.979192][ T8990] ? netlink_unicast+0x710/0x710 [ 68.984109][ T8990] ? aa_sock_msg_perm.isra.0+0xba/0x170 [ 68.989688][ T8990] ? apparmor_socket_sendmsg+0x2a/0x30 [ 68.995140][ T8990] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 69.002450][ T8990] ? security_socket_sendmsg+0x8d/0xc0 [ 69.007904][ T8990] ? netlink_unicast+0x710/0x710 [ 69.012831][ T8990] sock_sendmsg+0xd7/0x130 [ 69.017245][ T8990] ___sys_sendmsg+0x803/0x920 [ 69.021921][ T8990] ? copy_msghdr_from_user+0x440/0x440 [ 69.027375][ T8990] ? lock_downgrade+0x920/0x920 [ 69.032304][ T8990] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 69.038091][ T8990] ? lockdep_hardirqs_on+0x421/0x5e0 [ 69.043449][ T8990] ? __kasan_check_read+0x11/0x20 [ 69.048505][ T8990] ? mark_lock+0xc2/0x1220 [ 69.052915][ T8990] ? _raw_spin_unlock_irqrestore+0xa4/0xe0 [ 69.058711][ T8990] ? __kasan_check_read+0x11/0x20 [ 69.063730][ T8990] ? __lock_acquire+0x16f2/0x4a00 [ 69.068734][ T8990] ? debug_object_deactivate+0x320/0x320 [ 69.074360][ T8990] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 69.080508][ T8990] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 69.086754][ T8990] ? __fget_light+0x1a9/0x230 [ 69.091428][ T8990] ? __fdget+0x1b/0x20 [ 69.095484][ T8990] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 69.101817][ T8990] __sys_sendmsg+0x105/0x1d0 [ 69.106400][ T8990] ? __sys_sendmsg_sock+0xd0/0xd0 [ 69.111405][ T8990] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 69.117382][ T8990] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 69.122949][ T8990] ? do_syscall_64+0x26/0x760 [ 69.127702][ T8990] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 69.133764][ T8990] ? do_syscall_64+0x26/0x760 [ 69.138598][ T8990] __x64_sys_sendmsg+0x78/0xb0 [ 69.143345][ T8990] do_syscall_64+0xfa/0x760 [ 69.147829][ T8990] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 69.153709][ T8990] RIP: 0033:0x445279 [ 69.157587][ T8990] Code: e8 ac e8 ff ff 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 0b cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 69.177185][ T8990] RSP: 002b:00007fffac1fc178 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 69.185581][ T8990] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445279 [ 69.193541][ T8990] RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000005 [ 69.201499][ T8990] RBP: 0000000000010907 R08: 0000000000000000 R09: 00000000004002e0 [ 69.209471][ T8990] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402410 [ 69.217424][ T8990] R13: 00000000004024a0 R14: 0000000000000000 R15: 0000000000000000 [ 69.226912][ T8990] Kernel Offset: disabled [ 69.231238][ T8990] Rebooting in 86400 seconds..