================================================================== BUG: KASAN: use-after-free in __fib6_clean_all+0x296/0x2a0 net/ipv6/ip6_fib.c:2255 Read of size 8 at addr ffff88804e2e2000 by task syz-executor.1/12557 CPU: 0 PID: 12557 Comm: syz-executor.1 Not tainted 6.1.0-rc4-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 __fib6_clean_all+0x296/0x2a0 net/ipv6/ip6_fib.c:2255 rt6_sync_down_dev net/ipv6/route.c:4894 [inline] rt6_disable_ip+0x803/0x9f0 net/ipv6/route.c:4899 addrconf_ifdown.isra.0+0x11a/0x1920 net/ipv6/addrconf.c:3750 addrconf_notify+0xeb/0x1c10 net/ipv6/addrconf.c:3673 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] netdev_wait_allrefs_any net/core/dev.c:10237 [inline] netdev_run_todo+0xbc2/0x1100 net/core/dev.c:10351 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xe0/0x180 drivers/net/tun.c:3459 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16b/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb35/0x2a20 kernel/exit.c:820 do_group_exit+0xd0/0x2a0 kernel/exit.c:950 get_signal+0x21a1/0x2430 kernel/signal.c:2858 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:296 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7ff8549 Code: Unable to access opcode bytes at 0xf7ff851f. RSP: 002b:00000000f7ff3330 EFLAGS: 00000202 ORIG_RAX: 00000000000000c3 RAX: fffffffffffffff4 RBX: 00000000f7ff3400 RCX: 00000000f7ff334c RDX: 0000000000000003 RSI: 00000000f7ff3480 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 3720: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa1/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:576 [inline] kzalloc include/linux/slab.h:712 [inline] fib6_net_init net/ipv6/ip6_fib.c:2376 [inline] fib6_net_init+0x1d7/0xa20 net/ipv6/ip6_fib.c:2351 ops_init+0xb9/0x680 net/core/net_namespace.c:135 setup_net+0x5d1/0xc50 net/core/net_namespace.c:332 copy_net_ns+0x318/0x760 net/core/net_namespace.c:478 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __ia32_sys_unshare+0x2c/0x40 kernel/fork.c:3257 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 10: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2a/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xab/0x3b0 mm/slub.c:3674 fib6_net_exit+0x1c9/0x280 net/ipv6/ip6_fib.c:2438 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:601 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff88804e2e2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff88804e2e2000, ffff88804e2e2800) The buggy address belongs to the physical page: page:ffffea000138b800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804e2e7000 pfn:0x4e2e0 head:ffffea000138b800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4fff00000010200(slab|head|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000010200 ffffea00012eb608 ffffea0001365808 ffff888011842f00 raw: ffff88804e2e7000 0000000000080006 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 3720, tgid 3720 (syz-executor.1), ts 257117532890, free_ts 250466183569 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4288 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5555 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x191/0x3e0 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc_node_track_caller+0x45/0xc0 mm/slab_common.c:975 kmemdup+0x28/0x60 mm/util.c:129 kmemdup include/linux/fortify-string.h:585 [inline] ip_vs_control_net_init_sysctl net/netfilter/ipvs/ip_vs_ctl.c:4039 [inline] ip_vs_control_net_init+0x563/0x1670 net/netfilter/ipvs/ip_vs_ctl.c:4193 __ip_vs_init+0x21b/0x4d0 net/netfilter/ipvs/ip_vs_core.c:2310 ops_init+0xb9/0x680 net/core/net_namespace.c:135 setup_net+0x5d1/0xc50 net/core/net_namespace.c:332 copy_net_ns+0x318/0x760 net/core/net_namespace.c:478 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3483 __folio_put_large mm/swap.c:118 [inline] __folio_put+0x105/0x130 mm/swap.c:126 folio_put include/linux/mm.h:1159 [inline] put_page include/linux/mm.h:1211 [inline] __skb_frag_unref include/linux/skbuff.h:3385 [inline] skb_release_data+0x51e/0x870 net/core/skbuff.c:783 skb_release_all net/core/skbuff.c:854 [inline] __kfree_skb net/core/skbuff.c:868 [inline] skb_attempt_defer_free+0x300/0x3e0 net/core/skbuff.c:6638 tcp_eat_recv_skb net/ipv4/tcp.c:1638 [inline] tcp_recvmsg_locked+0x124e/0x22c0 net/ipv4/tcp.c:2633 tcp_recvmsg+0x113/0x620 net/ipv4/tcp.c:2679 inet_recvmsg+0x110/0x5d0 net/ipv4/af_inet.c:861 sock_recvmsg_nosec net/socket.c:995 [inline] sock_recvmsg net/socket.c:1013 [inline] sock_recvmsg net/socket.c:1009 [inline] sock_read_iter+0x344/0x470 net/socket.c:1086 call_read_iter include/linux/fs.h:2185 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x7f6/0x930 fs/read_write.c:470 ksys_read+0x1e8/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88804e2e1f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804e2e1f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88804e2e2000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804e2e2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804e2e2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================