netlink: 80 bytes leftover after parsing attributes in process `syz.0.17'. ================================================================== BUG: KASAN: slab-out-of-bounds in decode_session6 net/xfrm/xfrm_policy.c:3413 [inline] BUG: KASAN: slab-out-of-bounds in __xfrm_decode_session+0x17ae/0x1fa0 net/xfrm/xfrm_policy.c:3520 Read of size 1 at addr ffff88802321be8c by task syz.0.17/5103 CPU: 0 PID: 5103 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 decode_session6 net/xfrm/xfrm_policy.c:3413 [inline] __xfrm_decode_session+0x17ae/0x1fa0 net/xfrm/xfrm_policy.c:3520 xfrm_decode_session_reverse include/net/xfrm.h:1170 [inline] icmpv6_route_lookup+0x3ea/0x5a0 net/ipv6/icmp.c:394 icmp6_send+0xff2/0x1990 net/ipv6/icmp.c:601 __icmpv6_send include/linux/icmpv6.h:28 [inline] icmpv6_send include/linux/icmpv6.h:49 [inline] ip6_link_failure+0x35/0x490 net/ipv6/route.c:2789 dst_link_failure include/net/dst.h:422 [inline] ip6_tnl_xmit+0x671/0x23e0 net/ipv6/ip6_tunnel.c:1279 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1395 [inline] ip6_tnl_start_xmit+0xd27/0x12d0 net/ipv6/ip6_tunnel.c:1444 __netdev_start_xmit include/linux/netdevice.h:5036 [inline] netdev_start_xmit include/linux/netdevice.h:5050 [inline] xmit_one net/core/dev.c:3662 [inline] dev_hard_start_xmit+0x2a5/0x7e0 net/core/dev.c:3678 sch_direct_xmit+0x25a/0x4b0 net/sched/sch_generic.c:345 qdisc_restart net/sched/sch_generic.c:410 [inline] __qdisc_run+0xa7e/0x1490 net/sched/sch_generic.c:418 __dev_xmit_skb net/core/dev.c:3955 [inline] __dev_queue_xmit+0xe3d/0x2f80 net/core/dev.c:4266 neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0x108c/0x1510 net/ipv6/ip6_output.c:130 ip6_fragment+0x133d/0x1ee0 net/ipv6/ip6_output.c:998 dst_output include/net/dst.h:452 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip6_xmit+0x109b/0x16d0 net/ipv6/ip6_output.c:338 sctp_v6_xmit+0x985/0x11b0 net/sctp/ipv6.c:250 sctp_packet_transmit+0x239c/0x2910 net/sctp/output.c:652 sctp_packet_singleton+0x231/0x330 net/sctp/outqueue.c:780 sctp_outq_flush_ctrl net/sctp/outqueue.c:911 [inline] sctp_outq_flush+0x4ac/0x3100 net/sctp/outqueue.c:1209 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x4ee2/0x55f0 net/sctp/sm_sideeffect.c:1170 sctp_primitive_ASSOCIATE+0x91/0xc0 net/sctp/primitive.c:73 sctp_sendmsg_to_asoc+0x14a7/0x1d90 net/sctp/socket.c:1840 sctp_sendmsg+0x196a/0x2900 net/sctp/socket.c:2030 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499 __sys_sendmmsg+0x2ba/0x500 net/socket.c:2585 __do_sys_sendmmsg net/socket.c:2614 [inline] __se_sys_sendmmsg net/socket.c:2611 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2611 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f19521b3819 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 RSP: 002b:00007f1951815028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f195242cfa0 RCX: 00007f19521b3819 RDX: 0000000000000002 RSI: 0000200000002fc0 RDI: 0000000000000004 RBP: 00007f1952249c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000024000045 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f195242d038 R14: 00007f195242cfa0 R15: 00007ffcad8d4ff8 Allocated by task 4697: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] ops_init+0x8b/0x600 net/core/net_namespace.c:128 setup_net+0x39e/0xa10 net/core/net_namespace.c:333 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226 ksys_unshare+0x503/0x8c0 kernel/fork.c:3175 __do_sys_unshare kernel/fork.c:3249 [inline] __se_sys_unshare kernel/fork.c:3247 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3247 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 9: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 ops_free_list+0x27e/0x330 net/core/net_namespace.c:186 cleanup_net+0x7df/0xba0 net/core/net_namespace.c:639 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3011 [inline] call_rcu+0x189/0x950 kernel/rcu/tree.c:3091 in6_dev_put include/net/addrconf.h:386 [inline] addrconf_ifdown+0x1742/0x19c0 net/ipv6/addrconf.c:3931 addrconf_notify+0x445/0xf00 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] unregister_netdevice_many+0x1049/0x19f0 net/core/dev.c:11160 default_device_exit_batch+0x364/0x3c0 net/core/dev.c:11693 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x791/0xba0 net/core/net_namespace.c:635 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Second to last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1694 [inline] __run_timers+0x569/0x800 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 The buggy address belongs to the object at ffff88802321b000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1676 bytes to the right of 2048-byte region [ffff88802321b000, ffff88802321b800) The buggy address belongs to the page: page:ffffea00008c8600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23218 head:ffffea00008c8600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888016c42000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4249, ts 77553658569, free_ts 77532227362 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4963 kmalloc_reserve net/core/skbuff.c:356 [inline] pskb_expand_head+0x127/0x10f0 net/core/skbuff.c:1710 netlink_trim+0x180/0x220 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0x7c/0x1170 net/netlink/af_netlink.c:1511 netlink_broadcast net/netlink/af_netlink.c:1556 [inline] nlmsg_multicast include/net/netlink.h:1044 [inline] nlmsg_notify+0xec/0x1a0 net/netlink/af_netlink.c:2550 __dev_notify_flags+0xdc/0x300 net/core/dev.c:8913 rtnl_configure_link+0x21f/0x320 net/core/rtnetlink.c:-1 __rtnl_newlink net/core/rtnetlink.c:3537 [inline] rtnl_newlink+0x15be/0x1a50 net/core/rtnetlink.c:3577 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5687 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc_trace+0x103/0x2a0 mm/slub.c:3250 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] kset_create lib/kobject.c:982 [inline] kset_create_and_add+0x56/0x160 lib/kobject.c:1025 register_queue_kobjects net/core/net-sysfs.c:1759 [inline] netdev_register_kobject+0x1ae/0x320 net/core/net-sysfs.c:2018 register_netdevice+0x1042/0x1710 net/core/dev.c:10423 register_vlan_dev+0x393/0x810 net/8021q/vlan.c:180 vlan_newlink+0x44c/0x610 net/8021q/vlan_netlink.c:195 __rtnl_newlink net/core/rtnetlink.c:3529 [inline] rtnl_newlink+0x1359/0x1a50 net/core/rtnetlink.c:3577 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5687 Memory state around the buggy address: ffff88802321bd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802321be00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802321be80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88802321bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802321bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================