syzkaller syzkaller login: [ 9.445587][ T109] udevd (109) used greatest stack depth: 22888 bytes left [ 14.274801][ T30] kauditd_printk_skb: 31 callbacks suppressed [ 14.274817][ T30] audit: type=1400 audit(1787894505.099:59): avc: denied { transition } for pid=223 comm="sshd-session" path="/bin/sh" dev="sda1" ino=90 scontext=system_u:system_r:sshd_t tcontext=root:sysadm_r:sysadm_t tclass=process permissive=1 [ 14.285208][ T30] audit: type=1400 audit(1787894505.099:60): avc: denied { noatsecure } for pid=223 comm="sshd-session" scontext=system_u:system_r:sshd_t tcontext=root:sysadm_r:sysadm_t tclass=process permissive=1 [ 14.292264][ T30] audit: type=1400 audit(1787894505.109:61): avc: denied { write } for pid=223 comm="sh" path="pipe:[14911]" dev="pipefs" ino=14911 scontext=root:sysadm_r:sysadm_t tcontext=system_u:system_r:sshd_t tclass=fifo_file permissive=1 [ 14.310122][ T30] audit: type=1400 audit(1787894505.109:62): avc: denied { rlimitinh } for pid=223 comm="sh" scontext=system_u:system_r:sshd_t tcontext=root:sysadm_r:sysadm_t tclass=process permissive=1 [ 14.328928][ T30] audit: type=1400 audit(1787894505.109:63): avc: denied { siginh } for pid=223 comm="sh" scontext=system_u:system_r:sshd_t tcontext=root:sysadm_r:sysadm_t tclass=process permissive=1 [ 16.382955][ T231] scp (231) used greatest stack depth: 22184 bytes left Warning: Permanently added '10.128.0.5' (ED25519) to the list of known hosts. 2026/08/28 05:21:54 parsed 1 programs 2026/08/28 05:21:54 serving rpc on tcp://40333 [ 23.858607][ T30] audit: type=1400 audit(1787894514.689:64): avc: denied { node_bind } for pid=293 comm="syz-execprog" saddr=::1 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:node_t tclass=tcp_socket permissive=1 [ 23.879429][ T30] audit: type=1400 audit(1787894514.689:65): avc: denied { module_request } for pid=293 comm="syz-execprog" kmod="net-pf-2-proto-262-type-1" scontext=root:sysadm_r:sysadm_t tcontext=system_u:system_r:kernel_t tclass=system permissive=1 [ 24.880823][ T30] audit: type=1400 audit(1787894515.709:66): avc: denied { mounton } for pid=299 comm="syz-executor" path="/syzcgroup/unified" dev="sda1" ino=2024 scontext=root:sysadm_r:sysadm_t tcontext=root:object_r:root_t tclass=dir permissive=1 [ 24.885281][ T299] cgroup: Unknown subsys name 'net' [ 24.903511][ T30] audit: type=1400 audit(1787894515.709:67): avc: denied { mount } for pid=299 comm="syz-executor" name="/" dev="cgroup2" ino=1 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:cgroup_t tclass=filesystem permissive=1 [ 24.930862][ T30] audit: type=1400 audit(1787894515.739:68): avc: denied { unmount } for pid=299 comm="syz-executor" scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:cgroup_t tclass=filesystem permissive=1 [ 24.932125][ T299] cgroup: Unknown subsys name 'devices' [ 25.049735][ T299] cgroup: Unknown subsys name 'hugetlb' [ 25.055368][ T299] cgroup: Unknown subsys name 'rlimit' [ 25.232992][ T30] audit: type=1400 audit(1787894516.059:69): avc: denied { setattr } for pid=299 comm="syz-executor" name="raw-gadget" dev="devtmpfs" ino=254 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:device_t tclass=chr_file permissive=1 [ 25.256250][ T30] audit: type=1400 audit(1787894516.059:70): avc: denied { create } for pid=299 comm="syz-executor" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=netlink_generic_socket permissive=1 [ 25.276692][ T30] audit: type=1400 audit(1787894516.059:71): avc: denied { write } for pid=299 comm="syz-executor" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=netlink_generic_socket permissive=1 [ 25.297092][ T30] audit: type=1400 audit(1787894516.059:72): avc: denied { read } for pid=299 comm="syz-executor" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=netlink_generic_socket permissive=1 [ 25.316887][ T303] SELinux: Context root:object_r:swapfile_t is not valid (left unmapped). Setting up swapspace version 1, size = 127995904 bytes [ 25.317859][ T30] audit: type=1400 audit(1787894516.059:73): avc: denied { mounton } for pid=299 comm="syz-executor" path="/proc/sys/fs/binfmt_misc" dev="binfmt_misc" ino=1 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:binfmt_misc_fs_t tclass=dir permissive=1 [ 25.360023][ T299] Adding 124996k swap on ./swap-file. Priority:0 extents:1 across:124996k [ 25.803983][ T305] request_module fs-gadgetfs succeeded, but still no fs? [ 26.042777][ T319] bridge0: port 1(bridge_slave_0) entered blocking state [ 26.050089][ T319] bridge0: port 1(bridge_slave_0) entered disabled state [ 26.057847][ T319] device bridge_slave_0 entered promiscuous mode [ 26.065798][ T319] bridge0: port 2(bridge_slave_1) entered blocking state [ 26.072881][ T319] bridge0: port 2(bridge_slave_1) entered disabled state [ 26.080391][ T319] device bridge_slave_1 entered promiscuous mode [ 26.124642][ T319] bridge0: port 2(bridge_slave_1) entered blocking state [ 26.131736][ T319] bridge0: port 2(bridge_slave_1) entered forwarding state [ 26.139083][ T319] bridge0: port 1(bridge_slave_0) entered blocking state [ 26.146127][ T319] bridge0: port 1(bridge_slave_0) entered forwarding state [ 26.165436][ T10] bridge0: port 1(bridge_slave_0) entered disabled state [ 26.172796][ T10] bridge0: port 2(bridge_slave_1) entered disabled state [ 26.180381][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 26.188087][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 26.197985][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 26.206231][ T10] bridge0: port 1(bridge_slave_0) entered blocking state [ 26.213299][ T10] bridge0: port 1(bridge_slave_0) entered forwarding state [ 26.222276][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 26.230542][ T10] bridge0: port 2(bridge_slave_1) entered blocking state [ 26.237599][ T10] bridge0: port 2(bridge_slave_1) entered forwarding state [ 26.251102][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 26.260659][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 26.274576][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready [ 26.286235][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready [ 26.294379][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready [ 26.302093][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready [ 26.310359][ T319] device veth0_vlan entered promiscuous mode [ 26.321599][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready [ 26.330780][ T319] device veth1_macvtap entered promiscuous mode [ 26.340396][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready [ 26.350770][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready [ 26.402082][ T319] syz-executor (319) used greatest stack depth: 21984 bytes left [ 26.959280][ T45] device bridge_slave_1 left promiscuous mode [ 26.965588][ T45] bridge0: port 2(bridge_slave_1) entered disabled state [ 26.974041][ T45] device bridge_slave_0 left promiscuous mode [ 26.980387][ T45] bridge0: port 1(bridge_slave_0) entered disabled state [ 26.989394][ T45] device veth1_macvtap left promiscuous mode [ 26.995878][ T45] device veth0_vlan left promiscuous mode 2026/08/28 05:21:57 executed programs: 0 [ 27.199688][ T367] bridge0: port 1(bridge_slave_0) entered blocking state [ 27.206852][ T367] bridge0: port 1(bridge_slave_0) entered disabled state [ 27.214436][ T367] device bridge_slave_0 entered promiscuous mode [ 27.221380][ T367] bridge0: port 2(bridge_slave_1) entered blocking state [ 27.228457][ T367] bridge0: port 2(bridge_slave_1) entered disabled state [ 27.235819][ T367] device bridge_slave_1 entered promiscuous mode [ 27.287039][ T367] bridge0: port 2(bridge_slave_1) entered blocking state [ 27.294169][ T367] bridge0: port 2(bridge_slave_1) entered forwarding state [ 27.301583][ T367] bridge0: port 1(bridge_slave_0) entered blocking state [ 27.308643][ T367] bridge0: port 1(bridge_slave_0) entered forwarding state [ 27.329981][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 27.338036][ T10] bridge0: port 1(bridge_slave_0) entered disabled state [ 27.345214][ T10] bridge0: port 2(bridge_slave_1) entered disabled state [ 27.354384][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 27.362779][ T10] bridge0: port 1(bridge_slave_0) entered blocking state [ 27.369860][ T10] bridge0: port 1(bridge_slave_0) entered forwarding state [ 27.380563][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 27.388863][ T10] bridge0: port 2(bridge_slave_1) entered blocking state [ 27.395916][ T10] bridge0: port 2(bridge_slave_1) entered forwarding state [ 27.408410][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 27.417788][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 27.432006][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready [ 27.443162][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready [ 27.451272][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready [ 27.459390][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready [ 27.467712][ T367] device veth0_vlan entered promiscuous mode [ 27.477298][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready [ 27.486596][ T367] device veth1_macvtap entered promiscuous mode [ 27.495998][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready [ 27.506270][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready [ 27.531322][ T371] ================================================================== [ 27.539430][ T371] BUG: KASAN: use-after-free in mutex_lock+0x8e/0x1c0 [ 27.546216][ T371] Write of size 8 at addr ffff88812375cd50 by task syz.2.17/371 [ 27.553852][ T371] [ 27.556272][ T371] CPU: 1 PID: 371 Comm: syz.2.17 Not tainted syzkaller #0 [ 27.563377][ T371] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 [ 27.573449][ T371] Call Trace: [ 27.576737][ T371] [ 27.579671][ T371] __dump_stack+0x21/0x30 [ 27.584007][ T371] dump_stack_lvl+0x110/0x170 [ 27.588686][ T371] ? show_regs_print_info+0x20/0x20 [ 27.593884][ T371] ? load_image+0x3f0/0x3f0 [ 27.598423][ T371] print_address_description+0x7f/0x2c0 [ 27.604024][ T371] ? mutex_lock+0x8e/0x1c0 [ 27.608499][ T371] kasan_report+0x10f/0x150 [ 27.613042][ T371] ? mutex_lock+0x8e/0x1c0 [ 27.617482][ T371] kasan_check_range+0x249/0x2a0 [ 27.622446][ T371] __kasan_check_write+0x14/0x20 [ 27.627401][ T371] mutex_lock+0x8e/0x1c0 [ 27.631659][ T371] ? wait_for_completion_killable_timeout+0x10/0x10 [ 27.638264][ T371] ? l2tp_session_put+0xaf/0x1a0 [ 27.643217][ T371] ? l2tp_session_delete+0x3a9/0x4a0 [ 27.648521][ T371] pppol2tp_release+0x178/0x2b0 [ 27.653395][ T371] sock_close+0xb8/0x200 [ 27.657659][ T371] ? sock_mmap+0xa0/0xa0 [ 27.661921][ T371] __fput+0x22b/0x900 [ 27.665925][ T371] ____fput+0x15/0x20 [ 27.669927][ T371] task_work_run+0x127/0x190 [ 27.674534][ T371] exit_to_user_mode_loop+0xd0/0xe0 [ 27.679752][ T371] exit_to_user_mode_prepare+0x87/0xd0 [ 27.685222][ T371] syscall_exit_to_user_mode+0x1a/0x30 [ 27.690703][ T371] do_syscall_64+0x58/0xa0 [ 27.695133][ T371] ? clear_bhb_loop+0x50/0xa0 [ 27.699827][ T371] ? clear_bhb_loop+0x50/0xa0 [ 27.704519][ T371] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 27.710430][ T371] RIP: 0033:0x7fd666a900d9 [ 27.714880][ T371] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 [ 27.734514][ T371] RSP: 002b:00007ffe941a1398 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 [ 27.742942][ T371] RAX: 0000000000000000 RBX: 00007ffe941a1480 RCX: 00007fd666a900d9 [ 27.750950][ T371] RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 [ 27.758972][ T371] RBP: 0000000000006b6e R08: 0000000000000001 R09: 0000000000000000 [ 27.766958][ T371] R10: 0000001b32e20000 R11: 0000000000000246 R12: 0000000000000000 [ 27.774947][ T371] R13: 00007fd666d17fac R14: 00007fd666d17fa8 R15: 00007fd666d17fa0 [ 27.782940][ T371] [ 27.785970][ T371] [ 27.788303][ T371] Allocated by task 371: [ 27.792551][ T371] __kasan_kmalloc+0xd4/0x100 [ 27.797242][ T371] __kmalloc+0x13d/0x2c0 [ 27.801505][ T371] l2tp_session_create+0x39/0xb60 [ 27.806567][ T371] pppol2tp_connect+0xbf5/0x1640 [ 27.811517][ T371] __sys_connect+0x3cb/0x450 [ 27.816122][ T371] __x64_sys_connect+0x7a/0x90 [ 27.820894][ T371] x64_sys_call+0x7c/0x9a0 [ 27.825334][ T371] do_syscall_64+0x4c/0xa0 [ 27.829785][ T371] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 27.835695][ T371] [ 27.838027][ T371] Freed by task 371: [ 27.841932][ T371] kasan_set_track+0x4a/0x70 [ 27.846532][ T371] kasan_set_free_info+0x23/0x40 [ 27.851478][ T371] ____kasan_slab_free+0x125/0x160 [ 27.856603][ T371] __kasan_slab_free+0x11/0x20 [ 27.861381][ T371] slab_free_freelist_hook+0xc2/0x190 [ 27.866768][ T371] kfree+0xc4/0x270 [ 27.870592][ T371] l2tp_session_put+0xaf/0x1a0 [ 27.875377][ T371] l2tp_session_delete+0x3a9/0x4a0 [ 27.880503][ T371] pppol2tp_release+0x169/0x2b0 [ 27.885395][ T371] sock_close+0xb8/0x200 [ 27.889652][ T371] __fput+0x22b/0x900 [ 27.893653][ T371] ____fput+0x15/0x20 [ 27.897650][ T371] task_work_run+0x127/0x190 [ 27.902255][ T371] exit_to_user_mode_loop+0xd0/0xe0 [ 27.907488][ T371] exit_to_user_mode_prepare+0x87/0xd0 [ 27.912962][ T371] syscall_exit_to_user_mode+0x1a/0x30 [ 27.918434][ T371] do_syscall_64+0x58/0xa0 [ 27.922862][ T371] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 27.928783][ T371] [ 27.931112][ T371] The buggy address belongs to the object at ffff88812375cc00 [ 27.931112][ T371] which belongs to the cache kmalloc-512 of size 512 [ 27.945174][ T371] The buggy address is located 336 bytes inside of [ 27.945174][ T371] 512-byte region [ffff88812375cc00, ffff88812375ce00) [ 27.958467][ T371] The buggy address belongs to the page: [ 27.964144][ T371] page:ffffea00048dd700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12375c [ 27.974396][ T371] head:ffffea00048dd700 order:2 compound_mapcount:0 compound_pincount:0 [ 27.982730][ T371] flags: 0x4000000000010200(slab|head|zone=1) [ 27.988914][ T371] raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100042f00 [ 27.997516][ T371] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 28.006110][ T371] page dumped because: kasan: bad access detected [ 28.012529][ T371] page_owner tracks the page as allocated [ 28.018259][ T371] page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 367, ts 27518881184, free_ts 26550433962 [ 28.038698][ T371] post_alloc_hook+0x192/0x1b0 [ 28.043642][ T371] prep_new_page+0x1c/0x110 [ 28.048163][ T371] get_page_from_freelist+0x2c3a/0x2cd0 [ 28.053720][ T371] __alloc_pages+0x1a2/0x460 [ 28.058325][ T371] new_slab+0xa0/0x4d0 [ 28.062416][ T371] ___slab_alloc+0x3ac/0x840 [ 28.067022][ T371] __slab_alloc+0x49/0x90 [ 28.071364][ T371] __kmalloc_track_caller+0x169/0x2c0 [ 28.076760][ T371] __alloc_skb+0x210/0x730 [ 28.081185][ T371] netlink_sendmsg+0x611/0xb80 [ 28.085988][ T371] __sys_sendto+0x46d/0x620 [ 28.090503][ T371] __x64_sys_sendto+0xe5/0x100 [ 28.095298][ T371] x64_sys_call+0x178/0x9a0 [ 28.099816][ T371] do_syscall_64+0x4c/0xa0 [ 28.104250][ T371] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 28.110160][ T371] page last free stack trace: [ 28.114928][ T371] free_unref_page_prepare+0x5fa/0x600 [ 28.120432][ T371] free_unref_page+0xae/0x540 [ 28.125160][ T371] __free_pages+0x6c/0x100 [ 28.129587][ T371] __vunmap+0x801/0x980 [ 28.133751][ T371] vfree+0x8b/0xc0 [ 28.137482][ T371] kcov_close+0x2b/0x50 [ 28.141655][ T371] __fput+0x22b/0x900 [ 28.145654][ T371] ____fput+0x15/0x20 [ 28.149645][ T371] task_work_run+0x127/0x190 [ 28.154246][ T371] do_exit+0xb70/0x29a0 [ 28.158411][ T371] do_group_exit+0x149/0x310 [ 28.163012][ T371] get_signal+0x64f/0x1430 [ 28.167445][ T371] arch_do_signal_or_restart+0xe2/0x1100 [ 28.173088][ T371] exit_to_user_mode_loop+0xa7/0xe0 [ 28.178301][ T371] exit_to_user_mode_prepare+0x87/0xd0 [ 28.183771][ T371] syscall_exit_to_user_mode+0x1a/0x30 [ 28.189251][ T371] [ 28.191680][ T371] Memory state around the buggy address: [ 28.197313][ T371] ffff88812375cc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.205431][ T371] ffff88812375cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.213506][ T371] >ffff88812375cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.221569][ T371] ^ [ 28.228245][ T371] ffff88812375cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.236310][ T371] ffff88812375ce00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 28.244380][ T371] ================================================================== [ 28.252459][ T371] Disabling lock debugging due to kernel taint