================================================================== BUG: KASAN: slab-use-after-free in decode_session6 net/xfrm/xfrm_policy.c:3494 [inline] BUG: KASAN: slab-use-after-free in __xfrm_decode_session+0x18d7/0x20a0 net/xfrm/xfrm_policy.c:3600 Read of size 1 at addr ffff88802b84d6a0 by task syz.3.362/7050 CPU: 0 PID: 7050 Comm: syz.3.362 Not tainted 6.6.98-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x230 mm/kasan/report.c:475 kasan_report+0x117/0x150 mm/kasan/report.c:588 decode_session6 net/xfrm/xfrm_policy.c:3494 [inline] __xfrm_decode_session+0x18d7/0x20a0 net/xfrm/xfrm_policy.c:3600 xfrm_decode_session_reverse include/net/xfrm.h:1243 [inline] icmpv6_route_lookup+0x358/0x590 net/ipv6/icmp.c:392 icmp6_send+0x106a/0x1990 net/ipv6/icmp.c:604 __icmpv6_send include/linux/icmpv6.h:28 [inline] icmpv6_send include/linux/icmpv6.h:49 [inline] ip6_link_failure+0x3b/0x4c0 net/ipv6/route.c:2825 dst_link_failure include/net/dst.h:437 [inline] ip6_tnl_xmit+0xdf7/0x2a30 net/ipv6/ip6_tunnel.c:1283 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1399 [inline] ip6_tnl_start_xmit+0xc10/0x1140 net/ipv6/ip6_tunnel.c:1447 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3607 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3623 sch_direct_xmit+0x252/0x4a0 net/sched/sch_generic.c:342 qdisc_restart net/sched/sch_generic.c:407 [inline] __qdisc_run+0xab2/0x1570 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3907 [inline] __dev_queue_xmit+0xf02/0x35a0 net/core/dev.c:4379 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0xe2e/0x1650 net/ipv6/ip6_output.c:141 ip6_fragment+0x13c5/0x1f90 net/ipv6/ip6_output.c:1023 __ip6_finish_output net/ipv6/ip6_output.c:206 [inline] ip6_finish_output+0x5b4/0xaf0 net/ipv6/ip6_output.c:219 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ip6_xmit+0x10a7/0x1830 net/ipv6/ip6_output.c:360 sctp_v6_xmit+0x9e3/0x1230 net/sctp/ipv6.c:250 sctp_packet_transmit+0x2488/0x2a30 net/sctp/output.c:653 sctp_packet_singleton+0x234/0x330 net/sctp/outqueue.c:783 sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline] sctp_outq_flush+0x4f1/0x3100 net/sctp/outqueue.c:1212 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline] sctp_do_sm+0x52d6/0x59a0 net/sctp/sm_sideeffect.c:1169 sctp_primitive_ASSOCIATE+0x95/0xc0 net/sctp/primitive.c:73 __sctp_connect+0x92f/0xd20 net/sctp/socket.c:1234 sctp_setsockopt+0x458/0x11e0 net/sctp/socket.c:4617 do_sock_setsockopt+0x254/0x3e0 net/socket.c:2322 __sys_setsockopt net/socket.c:2345 [inline] __do_sys_setsockopt net/socket.c:2354 [inline] __se_sys_setsockopt net/socket.c:2351 [inline] __x64_sys_setsockopt+0x1be/0x250 net/socket.c:2351 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7efe5258e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007efe533dc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007efe527b5fa0 RCX: 00007efe5258e929 RDX: 000000000000006b RSI: 0000000000000084 RDI: 0000000000000003 RBP: 00007efe52610b39 R08: 000000000000001c R09: 0000000000000000 R10: 0000200000000380 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efe527b5fa0 R15: 00007ffda98fa358 Allocated by task 7048: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc+0xb4/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2094 sk_alloc+0x3a/0x360 net/core/sock.c:2147 __netlink_create+0x6c/0x290 net/netlink/af_netlink.c:630 netlink_create+0x3ee/0x5c0 net/netlink/af_netlink.c:691 __sock_create+0x4a6/0x940 net/socket.c:1571 sock_create net/socket.c:1627 [inline] __sys_socket_create net/socket.c:1664 [inline] __sys_socket+0xd7/0x1a0 net/socket.c:1715 __do_sys_socket net/socket.c:1729 [inline] __se_sys_socket net/socket.c:1727 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1727 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 7048: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1806 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832 slab_free mm/slub.c:3816 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829 sk_prot_free net/core/sock.c:2130 [inline] __sk_destruct+0x494/0x620 net/core/sock.c:2222 rcu_do_batch kernel/rcu/tree.c:2194 [inline] rcu_core+0xcc4/0x1720 kernel/rcu/tree.c:2467 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x158/0x930 kernel/rcu/tree.c:2837 netlink_release+0x16d8/0x1ad0 net/netlink/af_netlink.c:812 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1421 __fput+0x234/0x970 fs/file_table.c:384 __do_sys_close fs/open.c:1571 [inline] __se_sys_close+0x15f/0x220 fs/open.c:1556 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88802b84d000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1696 bytes inside of freed 2048-byte region [ffff88802b84d000, ffff88802b84d800) The buggy address belongs to the physical page: page:ffffea0000ae1200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b848 head:ffffea0000ae1200 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017842000 0000000000000000 0000000000000001 raw: 0000000000000000 0000000080080008 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 6790, tgid 6790 (syz-executor), ts 136633639214, free_ts 136601014255 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1876 allocate_slab mm/slub.c:2023 [inline] new_slab+0x87/0x2e0 mm/slub.c:2076 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230 __slab_alloc mm/slub.c:3329 [inline] __slab_alloc_node mm/slub.c:3382 [inline] slab_alloc_node mm/slub.c:3475 [inline] __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1284 [inline] nlmsg_new include/net/netlink.h:999 [inline] rtmsg_ifinfo_build_skb+0x8c/0x260 net/core/rtnetlink.c:4063 rtmsg_ifinfo_event net/core/rtnetlink.c:4106 [inline] rtmsg_ifinfo+0x8c/0x1a0 net/core/rtnetlink.c:4115 register_netdevice+0x1710/0x1ae0 net/core/dev.c:10315 __ip_tunnel_create+0x3b4/0x4c0 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x2c3/0x770 net/ipv4/ip_tunnel.c:1118 ops_init+0x397/0x640 net/core/net_namespace.c:139 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 __slab_free+0x35e/0x410 mm/slub.c:3722 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x13e/0x260 mm/slub.c:3524 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa4/0x240 mm/slab_common.c:1020 kmalloc_array include/linux/slab.h:637 [inline] memcg_list_lru_alloc+0x1af/0xae0 mm/list_lru.c:487 memcg_slab_pre_alloc_hook mm/slab.h:501 [inline] slab_pre_alloc_hook+0x2b6/0x310 mm/slab.h:719 slab_alloc_node mm/slub.c:3467 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc_lru+0x4d/0x2e0 mm/slub.c:3516 __d_alloc+0x31/0x730 fs/dcache.c:1773 d_alloc_anon fs/dcache.c:1872 [inline] d_make_root+0x4a/0xe0 fs/dcache.c:2075 jfs_fill_super+0x729/0xac0 fs/jfs/super.c:585 mount_bdev+0x22b/0x2d0 fs/super.c:1643 Memory state around the buggy address: ffff88802b84d580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802b84d600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802b84d680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802b84d700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802b84d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================