================================================================== BUG: KASAN: slab-out-of-bounds in xfrm_policy_inexact_list_reinsert+0x5d2/0x690 net/xfrm/xfrm_policy.c:874 Read of size 1 at addr ffff88801a5b0608 by task syz.3.493/5864 CPU: 0 PID: 5864 Comm: syz.3.493 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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 xfrm_policy_inexact_list_reinsert+0x5d2/0x690 net/xfrm/xfrm_policy.c:874 xfrm_policy_inexact_node_merge net/xfrm/xfrm_policy.c:1006 [inline] xfrm_policy_inexact_insert_node+0x950/0xb60 net/xfrm/xfrm_policy.c:1062 xfrm_policy_inexact_alloc_chain+0x7ce/0xea0 net/xfrm/xfrm_policy.c:1178 xfrm_policy_inexact_insert+0xe0/0x1460 net/xfrm/xfrm_policy.c:1221 xfrm_policy_insert+0x112/0x930 net/xfrm/xfrm_policy.c:1605 xfrm_add_policy+0x4f2/0x880 net/xfrm/xfrm_user.c:1833 xfrm_user_rcv_msg+0x5e5/0x910 net/xfrm/xfrm_user.c:2979 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 xfrm_netlink_rcv+0x75/0x90 net/xfrm/xfrm_user.c:3001 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 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_sendmsg net/socket.c:2528 [inline] __do_sys_sendmsg net/socket.c:2537 [inline] __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535 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: 0033:0x7ff7da0f8819 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:00007ff7d8352028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff7da371fa0 RCX: 00007ff7da0f8819 RDX: 0000000000000000 RSI: 0000200000000580 RDI: 000000000000000a RBP: 00007ff7da18ec91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff7da372038 R14: 00007ff7da371fa0 R15: 00007ffec1abbd48 Allocated by task 5864: 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] sk_prot_alloc+0xe7/0x210 net/core/sock.c:1866 sk_alloc+0x2f/0x310 net/core/sock.c:1922 pfkey_create+0xd8/0x560 net/key/af_key.c:152 __sock_create+0x47b/0x900 net/socket.c:1495 sock_create net/socket.c:1551 [inline] __sys_socket+0xe2/0x170 net/socket.c:1593 __do_sys_socket net/socket.c:1602 [inline] __se_sys_socket net/socket.c:1600 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1600 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 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 qdisc_put net/sched/sch_generic.c:1047 [inline] shutdown_scheduler_queue net/sched/sch_generic.c:1100 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2388 [inline] dev_shutdown+0x19f/0x710 net/sched/sch_generic.c:1408 unregister_netdevice_many+0xa2c/0x19f0 net/core/dev.c:11153 unregister_netdevice_queue+0x324/0x370 net/core/dev.c:11093 unregister_netdevice include/linux/netdevice.h:3029 [inline] __tun_detach+0xd4a/0x1500 drivers/net/tun.c:686 tun_detach drivers/net/tun.c:702 [inline] tun_chr_close+0x109/0x1b0 drivers/net/tun.c:3440 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88801a5b0000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1544 bytes inside of 2048-byte region [ffff88801a5b0000, ffff88801a5b0800) The buggy address belongs to the page: page:ffffea0000696c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a5b0 head:ffffea0000696c00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4184, ts 66813791594, free_ts 66768157393 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] slab_alloc mm/slub.c:3233 [inline] __kmalloc_track_caller+0x1cb/0x330 mm/slub.c:4930 kmemdup+0x22/0x50 mm/util.c:128 neigh_sysctl_register+0xaa/0xa90 net/core/neighbour.c:3652 devinet_sysctl_register+0xa8/0x1f0 net/ipv4/devinet.c:2640 inetdev_init+0x28c/0x4d0 net/ipv4/devinet.c:277 inetdev_event+0x26f/0x1370 net/ipv4/devinet.c:1543 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] register_netdevice+0x12a6/0x1710 net/core/dev.c:10454 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x32d/0x3e0 drivers/net/netdevsim/netdev.c:365 __nsim_dev_port_add+0x698/0xab0 drivers/net/netdevsim/dev.c:1312 nsim_dev_port_add_all+0x37/0x100 drivers/net/netdevsim/dev.c:1372 nsim_dev_probe+0x763/0x9c0 drivers/net/netdevsim/dev.c:1513 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 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] nsim_dev_traps_init+0x5c/0x480 drivers/net/netdevsim/dev.c:777 nsim_dev_probe+0x611/0x9c0 drivers/net/netdevsim/dev.c:1487 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 Memory state around the buggy address: ffff88801a5b0500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88801a5b0580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc >ffff88801a5b0600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88801a5b0680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801a5b0700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================