================================================================== BUG: KASAN: slab-use-after-free in rose_get_neigh+0x391/0x990 net/rose/rose_route.c:692 Read of size 1 at addr ffff8880600f6030 by task syz.2.5056/21088 CPU: 1 PID: 21088 Comm: syz.2.5056 Not tainted 6.6.94-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 rose_get_neigh+0x391/0x990 net/rose/rose_route.c:692 rose_connect+0x417/0x10a0 net/rose/af_rose.c:816 __sys_connect_file net/socket.c:2057 [inline] __sys_connect+0x397/0x420 net/socket.c:2074 __do_sys_connect net/socket.c:2084 [inline] __se_sys_connect net/socket.c:2081 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2081 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: 0033:0x7f152698e929 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:00007f1527798038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00007f1526bb5fa0 RCX: 00007f152698e929 RDX: 000000000000001c RSI: 0000200000000040 RDI: 0000000000000004 RBP: 00007f1526a10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1526bb5fa0 R15: 00007ffc84b5e888 Allocated by task 20565: 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 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] mca_alloc net/ipv6/mcast.c:880 [inline] __ipv6_dev_mc_inc+0x413/0xac0 net/ipv6/mcast.c:936 ipv6_add_dev+0xd75/0x11f0 net/ipv6/addrconf.c:466 addrconf_notify+0x67b/0x1010 net/ipv6/addrconf.c:3628 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] register_netdevice+0x160c/0x1ae0 net/core/dev.c:10301 veth_newlink+0x7bb/0xc30 drivers/net/veth.c:1902 rtnl_newlink_create net/core/rtnetlink.c:3517 [inline] __rtnl_newlink net/core/rtnetlink.c:3737 [inline] rtnl_newlink+0x14d0/0x2020 net/core/rtnetlink.c:3750 rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2537 netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline] netlink_unicast+0x750/0x8c0 net/netlink/af_netlink.c:1349 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x46a/0x620 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 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 23: 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_bulk+0x347/0x460 mm/slub.c:3934 kfree_bulk include/linux/slab.h:517 [inline] kvfree_rcu_bulk+0x1eb/0x470 kernel/rcu/tree.c:3028 kvfree_rcu_drain_ready kernel/rcu/tree.c:3212 [inline] kfree_rcu_monitor+0x7e7/0xf50 kernel/rcu/tree.c:3230 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3448 __ipv6_dev_mc_dec+0x2cc/0x330 net/ipv6/mcast.c:982 ipv6_mc_destroy_dev+0x338/0x590 net/ipv6/mcast.c:2805 addrconf_ifdown+0x139f/0x1880 net/ipv6/addrconf.c:3974 addrconf_notify+0x6c6/0x1010 net/ipv6/addrconf.c:-1 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] unregister_netdevice_many_notify+0xf36/0x1810 net/core/dev.c:11074 unregister_netdevice_many net/core/dev.c:11130 [inline] default_device_exit_batch+0x9cb/0xa60 net/core/dev.c:11608 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x77f/0xb90 net/core/net_namespace.c:652 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Second to 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 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3448 __ipv6_dev_mc_dec+0x2cc/0x330 net/ipv6/mcast.c:982 ipv6_mc_destroy_dev+0x338/0x590 net/ipv6/mcast.c:2805 addrconf_ifdown+0x139f/0x1880 net/ipv6/addrconf.c:3974 addrconf_notify+0x6c6/0x1010 net/ipv6/addrconf.c:-1 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] unregister_netdevice_many_notify+0xf36/0x1810 net/core/dev.c:11074 unregister_netdevice_many net/core/dev.c:11130 [inline] unregister_netdevice_queue+0x324/0x360 net/core/dev.c:11010 unregister_netdevice include/linux/netdevice.h:3136 [inline] __tun_detach+0xd45/0x1500 drivers/net/tun.c:685 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0x10d/0x1c0 drivers/net/tun.c:3511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff8880600f6000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 48 bytes inside of freed 512-byte region [ffff8880600f6000, ffff8880600f6200) The buggy address belongs to the physical page: page:ffffea0001803d00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x600f4 head:ffffea0001803d00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017841c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5777, tgid 5777 (syz-executor), ts 88601907385, free_ts 27463876271 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+0xa4/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] fib6_info_alloc+0x32/0xe0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x44f/0x1200 net/ipv6/route.c:3793 addrconf_f6i_alloc+0x1c6/0x400 net/ipv6/route.c:4621 ipv6_add_addr+0x576/0x1090 net/ipv6/addrconf.c:1129 addrconf_add_linklocal+0x289/0x6b0 net/ipv6/addrconf.c:3285 addrconf_addr_gen+0x4ac/0x5a0 net/ipv6/addrconf.c:3416 addrconf_init_auto_addrs+0x719/0xb40 net/ipv6/addrconf.c:-1 addrconf_notify+0xb62/0x1010 net/ipv6/addrconf.c:3718 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 free_contig_range+0xa1/0x160 mm/page_alloc.c:6369 destroy_args+0x87/0x770 mm/debug_vm_pgtable.c:1015 debug_vm_pgtable+0x3cc/0x410 mm/debug_vm_pgtable.c:1395 do_one_initcall+0x1fd/0x750 init/main.c:1238 do_initcall_level+0x137/0x1f0 init/main.c:1300 do_initcalls+0x69/0xd0 init/main.c:1316 kernel_init_freeable+0x3d2/0x570 init/main.c:1553 kernel_init+0x1d/0x1c0 init/main.c:1443 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Memory state around the buggy address: ffff8880600f5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880600f5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880600f6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880600f6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880600f6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================