================================================================== BUG: KASAN: use-after-free in __fib6_clean_all+0x296/0x2a0 net/ipv6/ip6_fib.c:2255 Read of size 8 at addr ffff88807cdb6000 by task syz-executor.1/18748 CPU: 0 PID: 18748 Comm: syz-executor.1 Not tainted 5.19.0-rc1-syzkaller-00263-gd7dd6eccfbc9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 __fib6_clean_all+0x296/0x2a0 net/ipv6/ip6_fib.c:2255 rt6_sync_down_dev net/ipv6/route.c:4887 [inline] rt6_disable_ip+0x7b7/0x9a0 net/ipv6/route.c:4892 addrconf_ifdown.isra.0+0x11a/0x1830 net/ipv6/addrconf.c:3750 addrconf_notify+0xeb/0x1ba0 net/ipv6/addrconf.c:3673 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1943 call_netdevice_notifiers_extack net/core/dev.c:1981 [inline] call_netdevice_notifiers net/core/dev.c:1995 [inline] netdev_wait_allrefs_any net/core/dev.c:10225 [inline] netdev_run_todo+0xb90/0x10b0 net/core/dev.c:10337 tun_detach drivers/net/tun.c:695 [inline] tun_chr_close+0xe0/0x180 drivers/net/tun.c:3444 __fput+0x277/0x9d0 fs/file_table.c:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xaff/0x2a00 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x2542/0x2600 kernel/signal.c:2857 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f3924c88277 Code: Unable to access opcode bytes at RIP 0x7f3924c8824d. RSP: 002b:00007ffebd551938 EFLAGS: 00000246 ORIG_RAX: 0000000000000050 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f3924c88277 RDX: 0000000000000001 RSI: 00007f3924d6eef0 RDI: 00007ffebd5519c0 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f3924d6eef0 R10: 00005555571e7400 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffebd551a00 Allocated by task 3619: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] fib6_net_init net/ipv6/ip6_fib.c:2376 [inline] fib6_net_init+0x1d7/0xa20 net/ipv6/ip6_fib.c:2351 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 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:3165 __do_sys_unshare kernel/fork.c:3236 [inline] __se_sys_unshare kernel/fork.c:3234 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3234 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+0x46/0xb0 Freed by task 6617: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1727 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1753 slab_free mm/slub.c:3507 [inline] kfree+0xd6/0x4d0 mm/slub.c:4555 fib6_net_exit+0x1c9/0x280 net/ipv6/ip6_fib.c:2438 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 The buggy address belongs to the object at ffff88807cdb6000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff88807cdb6000, ffff88807cdb6800) The buggy address belongs to the physical page: page:ffffea0001f36c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7cdb0 head:ffffea0001f36c00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888011842000 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 3619, tgid 3619 (syz-executor.1), ts 68646079117, free_ts 64026279561 prep_new_page mm/page_alloc.c:2456 [inline] get_page_from_freelist+0x1290/0x3b70 mm/page_alloc.c:4198 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5426 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1797 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1942 new_slab mm/slub.c:2002 [inline] ___slab_alloc+0x985/0xd90 mm/slub.c:3002 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3089 slab_alloc_node mm/slub.c:3180 [inline] slab_alloc mm/slub.c:3222 [inline] __kmalloc+0x318/0x350 mm/slub.c:4413 kmalloc include/linux/slab.h:605 [inline] sk_prot_alloc+0x110/0x290 net/core/sock.c:1975 sk_alloc+0x36/0x770 net/core/sock.c:2028 __netlink_create+0x63/0x2f0 net/netlink/af_netlink.c:647 __netlink_kernel_create+0x110/0x850 net/netlink/af_netlink.c:2045 netlink_kernel_create include/linux/netlink.h:62 [inline] crypto_netlink_init+0x98/0x120 crypto/crypto_user_base.c:486 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1371 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1421 free_unref_page_prepare mm/page_alloc.c:3343 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3438 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2521 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [inline] slab_alloc_node mm/slub.c:3214 [inline] __kmalloc_node_track_caller+0x238/0x360 mm/slub.c:4950 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb_fclone include/linux/skbuff.h:1476 [inline] tcp_stream_alloc_skb+0x66/0x900 net/ipv4/tcp.c:862 tcp_sendmsg_locked+0xad1/0x2fc0 net/ipv4/tcp.c:1297 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1448 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 sock_write_iter+0x284/0x3c0 net/socket.c:1108 call_write_iter include/linux/fs.h:2058 [inline] new_sync_write+0x38a/0x560 fs/read_write.c:504 vfs_write+0x7c0/0xac0 fs/read_write.c:591 Memory state around the buggy address: ffff88807cdb5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807cdb5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807cdb6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807cdb6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807cdb6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================