syzkaller syzkaller login: [ 9.028999][ T107] udevd (107) used greatest stack depth: 22888 bytes left [ 15.055651][ T30] kauditd_printk_skb: 2 callbacks suppressed [ 15.055678][ T30] audit: type=1400 audit(1784573058.136:59): 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 [ 15.067611][ T30] audit: type=1400 audit(1784573058.136:60): 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 [ 15.075599][ T30] audit: type=1400 audit(1784573058.146:61): avc: denied { write } for pid=223 comm="sh" path="pipe:[14577]" dev="pipefs" ino=14577 scontext=root:sysadm_r:sysadm_t tcontext=system_u:system_r:sshd_t tclass=fifo_file permissive=1 [ 15.100761][ T30] audit: type=1400 audit(1784573058.146:62): 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 [ 15.119404][ T30] audit: type=1400 audit(1784573058.146:63): 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 Warning: Permanently added '10.128.1.66' (ED25519) to the list of known hosts. 2026/07/20 18:44:27 parsed 1 programs 2026/07/20 18:44:27 serving rpc on tcp://38847 [ 24.454027][ T30] audit: type=1400 audit(1784573067.536:64): 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 [ 24.475201][ T30] audit: type=1400 audit(1784573067.536:65): 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 [ 25.333115][ T30] audit: type=1400 audit(1784573068.416:66): 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 [ 25.336125][ T299] cgroup: Unknown subsys name 'net' [ 25.355921][ T30] audit: type=1400 audit(1784573068.416:67): 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 [ 25.383141][ T30] audit: type=1400 audit(1784573068.456:68): 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 [ 25.383455][ T299] cgroup: Unknown subsys name 'devices' [ 25.529740][ T299] cgroup: Unknown subsys name 'hugetlb' [ 25.535433][ T299] cgroup: Unknown subsys name 'rlimit' [ 25.681941][ T30] audit: type=1400 audit(1784573068.766:69): 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 [ 25.705201][ T30] audit: type=1400 audit(1784573068.766:70): 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 [ 25.725576][ T30] audit: type=1400 audit(1784573068.766:71): 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 [ 25.745835][ T30] audit: type=1400 audit(1784573068.766:72): 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 [ 25.766032][ T30] audit: type=1400 audit(1784573068.766:73): 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 [ 25.780456][ T303] SELinux: Context root:object_r:swapfile_t is not valid (left unmapped). Setting up swapspace version 1, size = 127995904 bytes [ 25.855977][ T299] Adding 124996k swap on ./swap-file. Priority:0 extents:1 across:124996k [ 26.247002][ T306] request_module fs-gadgetfs succeeded, but still no fs? [ 26.610209][ T334] bridge0: port 1(bridge_slave_0) entered blocking state [ 26.617280][ T334] bridge0: port 1(bridge_slave_0) entered disabled state [ 26.624728][ T334] device bridge_slave_0 entered promiscuous mode [ 26.631460][ T334] bridge0: port 2(bridge_slave_1) entered blocking state [ 26.638508][ T334] bridge0: port 2(bridge_slave_1) entered disabled state [ 26.645868][ T334] device bridge_slave_1 entered promiscuous mode [ 26.684421][ T334] bridge0: port 2(bridge_slave_1) entered blocking state [ 26.691480][ T334] bridge0: port 2(bridge_slave_1) entered forwarding state [ 26.698820][ T334] bridge0: port 1(bridge_slave_0) entered blocking state [ 26.705853][ T334] bridge0: port 1(bridge_slave_0) entered forwarding state [ 26.723891][ T10] bridge0: port 1(bridge_slave_0) entered disabled state [ 26.731383][ T10] bridge0: port 2(bridge_slave_1) entered disabled state [ 26.738809][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 26.746209][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 26.755762][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 26.763927][ T10] bridge0: port 1(bridge_slave_0) entered blocking state [ 26.770976][ T10] bridge0: port 1(bridge_slave_0) entered forwarding state [ 26.779451][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 26.787604][ T10] bridge0: port 2(bridge_slave_1) entered blocking state [ 26.794651][ T10] bridge0: port 2(bridge_slave_1) entered forwarding state [ 26.807876][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 26.823308][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 26.831982][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready [ 26.843077][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready [ 26.851177][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready [ 26.858699][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready [ 26.866566][ T334] device veth0_vlan entered promiscuous mode [ 26.876028][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready [ 26.885293][ T334] device veth1_macvtap entered promiscuous mode [ 26.894642][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready [ 26.904301][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready [ 26.931067][ T334] syz-executor (334) used greatest stack depth: 20736 bytes left 2026/07/20 18:44:30 executed programs: 0 [ 27.443410][ T369] bridge0: port 1(bridge_slave_0) entered blocking state [ 27.450718][ T369] bridge0: port 1(bridge_slave_0) entered disabled state [ 27.458035][ T369] device bridge_slave_0 entered promiscuous mode [ 27.465206][ T369] bridge0: port 2(bridge_slave_1) entered blocking state [ 27.472342][ T369] bridge0: port 2(bridge_slave_1) entered disabled state [ 27.479684][ T369] device bridge_slave_1 entered promiscuous mode [ 27.522583][ T369] bridge0: port 2(bridge_slave_1) entered blocking state [ 27.529620][ T369] bridge0: port 2(bridge_slave_1) entered forwarding state [ 27.536844][ T369] bridge0: port 1(bridge_slave_0) entered blocking state [ 27.543893][ T369] bridge0: port 1(bridge_slave_0) entered forwarding state [ 27.564655][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 27.572906][ T10] bridge0: port 1(bridge_slave_0) entered disabled state [ 27.580337][ T10] bridge0: port 2(bridge_slave_1) entered disabled state [ 27.599752][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 27.607976][ T10] bridge0: port 1(bridge_slave_0) entered blocking state [ 27.615038][ T10] bridge0: port 1(bridge_slave_0) entered forwarding state [ 27.622920][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 27.631257][ T10] bridge0: port 2(bridge_slave_1) entered blocking state [ 27.638316][ T10] bridge0: port 2(bridge_slave_1) entered forwarding state [ 27.645698][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 27.654746][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 27.668005][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_virt_wifi: link becomes ready [ 27.676510][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready [ 27.688583][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready [ 27.696743][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready [ 27.704881][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready [ 27.712299][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready [ 27.720057][ T369] device veth0_vlan entered promiscuous mode [ 27.729679][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready [ 27.737820][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready [ 27.747418][ T369] device veth1_macvtap entered promiscuous mode [ 27.757341][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready [ 27.765070][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready [ 27.773403][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready [ 27.782834][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready [ 27.790970][ T10] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready [ 27.812690][ T374] ================================================================== [ 27.820807][ T374] BUG: KASAN: use-after-free in mutex_lock+0x8e/0x1c0 [ 27.827597][ T374] Write of size 8 at addr ffff888129523950 by task syz.2.17/374 [ 27.835233][ T374] [ 27.837567][ T374] CPU: 0 PID: 374 Comm: syz.2.17 Not tainted syzkaller #0 [ 27.844682][ T374] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 [ 27.854753][ T374] Call Trace: [ 27.858034][ T374] [ 27.860986][ T374] __dump_stack+0x21/0x30 [ 27.865318][ T374] dump_stack_lvl+0x110/0x170 [ 27.870001][ T374] ? show_regs_print_info+0x20/0x20 [ 27.875202][ T374] ? load_image+0x3f0/0x3f0 [ 27.879717][ T374] print_address_description+0x7f/0x2c0 [ 27.885278][ T374] ? mutex_lock+0x8e/0x1c0 [ 27.889709][ T374] kasan_report+0x10f/0x150 [ 27.894218][ T374] ? mutex_lock+0x8e/0x1c0 [ 27.898631][ T374] kasan_check_range+0x249/0x2a0 [ 27.903567][ T374] __kasan_check_write+0x14/0x20 [ 27.908507][ T374] mutex_lock+0x8e/0x1c0 [ 27.912757][ T374] ? wait_for_completion_killable_timeout+0x10/0x10 [ 27.919373][ T374] ? l2tp_session_put+0xaf/0x1a0 [ 27.924316][ T374] ? l2tp_session_delete+0x3a9/0x4a0 [ 27.929604][ T374] pppol2tp_release+0x178/0x2b0 [ 27.934464][ T374] sock_close+0xb8/0x200 [ 27.938735][ T374] ? sock_mmap+0xa0/0xa0 [ 27.942987][ T374] __fput+0x22b/0x900 [ 27.946974][ T374] ____fput+0x15/0x20 [ 27.951028][ T374] task_work_run+0x127/0x190 [ 27.955655][ T374] exit_to_user_mode_loop+0xd0/0xe0 [ 27.960878][ T374] exit_to_user_mode_prepare+0x87/0xd0 [ 27.966339][ T374] syscall_exit_to_user_mode+0x1a/0x30 [ 27.971818][ T374] do_syscall_64+0x58/0xa0 [ 27.976228][ T374] ? clear_bhb_loop+0x50/0xa0 [ 27.980901][ T374] ? clear_bhb_loop+0x50/0xa0 [ 27.985581][ T374] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 27.991491][ T374] RIP: 0033:0x7f62d7ba6e99 [ 27.995908][ T374] 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 [ 28.015629][ T374] RSP: 002b:00007fffa6408898 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 [ 28.024102][ T374] RAX: 0000000000000000 RBX: 00007fffa6408980 RCX: 00007f62d7ba6e99 [ 28.032080][ T374] RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 [ 28.040051][ T374] RBP: 0000000000006c87 R08: 0000000000000001 R09: 0000000000000000 [ 28.048292][ T374] R10: 0000001b33020000 R11: 0000000000000246 R12: 0000000000000000 [ 28.056272][ T374] R13: 00007f62d7e2efac R14: 00007f62d7e2efa8 R15: 00007f62d7e2efa0 [ 28.064251][ T374] [ 28.067276][ T374] [ 28.069604][ T374] Allocated by task 374: [ 28.073955][ T374] __kasan_kmalloc+0xd4/0x100 [ 28.078633][ T374] __kmalloc+0x13d/0x2c0 [ 28.082875][ T374] l2tp_session_create+0x39/0xb60 [ 28.087907][ T374] pppol2tp_connect+0xbf5/0x1640 [ 28.092848][ T374] __sys_connect+0x3cb/0x450 [ 28.097433][ T374] __x64_sys_connect+0x7a/0x90 [ 28.102217][ T374] x64_sys_call+0x7c/0x9a0 [ 28.106636][ T374] do_syscall_64+0x4c/0xa0 [ 28.111058][ T374] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 28.116977][ T374] [ 28.119320][ T374] Freed by task 374: [ 28.123214][ T374] kasan_set_track+0x4a/0x70 [ 28.127807][ T374] kasan_set_free_info+0x23/0x40 [ 28.132752][ T374] ____kasan_slab_free+0x125/0x160 [ 28.137882][ T374] __kasan_slab_free+0x11/0x20 [ 28.142652][ T374] slab_free_freelist_hook+0xc2/0x190 [ 28.148021][ T374] kfree+0xc4/0x270 [ 28.151833][ T374] l2tp_session_put+0xaf/0x1a0 [ 28.156597][ T374] l2tp_session_delete+0x3a9/0x4a0 [ 28.161706][ T374] pppol2tp_release+0x169/0x2b0 [ 28.166553][ T374] sock_close+0xb8/0x200 [ 28.170804][ T374] __fput+0x22b/0x900 [ 28.174796][ T374] ____fput+0x15/0x20 [ 28.178780][ T374] task_work_run+0x127/0x190 [ 28.183366][ T374] exit_to_user_mode_loop+0xd0/0xe0 [ 28.188563][ T374] exit_to_user_mode_prepare+0x87/0xd0 [ 28.194033][ T374] syscall_exit_to_user_mode+0x1a/0x30 [ 28.199518][ T374] do_syscall_64+0x58/0xa0 [ 28.203952][ T374] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 28.209853][ T374] [ 28.212176][ T374] The buggy address belongs to the object at ffff888129523800 [ 28.212176][ T374] which belongs to the cache kmalloc-512 of size 512 [ 28.226233][ T374] The buggy address is located 336 bytes inside of [ 28.226233][ T374] 512-byte region [ffff888129523800, ffff888129523a00) [ 28.239511][ T374] The buggy address belongs to the page: [ 28.245150][ T374] page:ffffea0004a54800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x129520 [ 28.255399][ T374] head:ffffea0004a54800 order:2 compound_mapcount:0 compound_pincount:0 [ 28.263729][ T374] flags: 0x4000000000010200(slab|head|zone=1) [ 28.269800][ T374] raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100042f00 [ 28.278388][ T374] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 28.286969][ T374] page dumped because: kasan: bad access detected [ 28.293375][ T374] page_owner tracks the page as allocated [ 28.299085][ T374] 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 374, ts 27812488785, free_ts 27755530707 [ 28.319487][ T374] post_alloc_hook+0x192/0x1b0 [ 28.324252][ T374] prep_new_page+0x1c/0x110 [ 28.328756][ T374] get_page_from_freelist+0x2c3a/0x2cd0 [ 28.334310][ T374] __alloc_pages+0x1a2/0x460 [ 28.338900][ T374] new_slab+0xa0/0x4d0 [ 28.342970][ T374] ___slab_alloc+0x3ac/0x840 [ 28.347556][ T374] __slab_alloc+0x49/0x90 [ 28.351890][ T374] __kmalloc+0x16a/0x2c0 [ 28.356136][ T374] l2tp_session_create+0x39/0xb60 [ 28.361168][ T374] pppol2tp_connect+0xbf5/0x1640 [ 28.366110][ T374] __sys_connect+0x3cb/0x450 [ 28.370697][ T374] __x64_sys_connect+0x7a/0x90 [ 28.375461][ T374] x64_sys_call+0x7c/0x9a0 [ 28.379882][ T374] do_syscall_64+0x4c/0xa0 [ 28.384301][ T374] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 28.390224][ T374] page last free stack trace: [ 28.394894][ T374] free_unref_page_prepare+0x5fa/0x600 [ 28.400364][ T374] free_unref_page+0xae/0x540 [ 28.405050][ T374] __free_pages+0x6c/0x100 [ 28.409475][ T374] free_nonslab_page+0x86/0xc0 [ 28.414238][ T374] kfree+0x19a/0x270 [ 28.418127][ T374] tipc_nametbl_stop+0x1294/0x12f0 [ 28.423249][ T374] tipc_exit_net+0x99/0x190 [ 28.427756][ T374] cleanup_net+0x58e/0xae0 [ 28.432173][ T374] process_one_work+0x6c8/0xbb0 [ 28.437026][ T374] worker_thread+0xaa0/0x1250 [ 28.441706][ T374] kthread+0x3f5/0x4f0 [ 28.445770][ T374] ret_from_fork+0x1f/0x30 [ 28.450184][ T374] [ 28.452509][ T374] Memory state around the buggy address: [ 28.458132][ T374] ffff888129523800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.466190][ T374] ffff888129523880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.474249][ T374] >ffff888129523900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.482307][ T374] ^ [ 28.488974][ T374] ffff888129523980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.497029][ T374] ffff888129523a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 28.505088][ T374] ================================================================== [ 28.513145][ T374] Disabling lock debugging due to kernel taint