================================================================== BUG: KASAN: use-after-free in dev_net include/linux/netdevice.h:2220 [inline] BUG: KASAN: use-after-free in ipv6_get_ifaddr+0x4b6/0x560 net/ipv6/addrconf.c:2001 Read of size 8 at addr ffff88805b93e588 by task kworker/1:24/2745 CPU: 1 PID: 2745 Comm: kworker/1:24 Not tainted 5.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: rcu_gp process_srcu Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 dev_net include/linux/netdevice.h:2220 [inline] ipv6_get_ifaddr+0x4b6/0x560 net/ipv6/addrconf.c:2001 ndisc_send_rs+0x188/0x720 net/ipv6/ndisc.c:668 addrconf_rs_timer+0x30f/0x6e0 net/ipv6/addrconf.c:3879 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1146 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:queue_delayed_work_on+0x12a/0x210 kernel/workqueue.c:1673 Code: 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 d8 00 00 00 48 83 3d 1e 2f 66 08 00 0f 84 9a 00 00 00 e8 8b 0f 28 00 48 89 df 57 9d <0f> 1f 44 00 00 e8 7c 0f 28 00 44 89 f8 48 83 c4 10 5b 41 5c 41 5d RSP: 0018:ffffc90008637bd0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8880a0162400 RBX: 0000000000000293 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff814d81a5 RDI: 0000000000000293 RBP: ffffc90008637c08 R08: 1ffffffff16a3371 R09: fffffbfff16a3372 R10: fffffbfff16a3371 R11: ffffffff8b519b8f R12: 0000000000000200 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 queue_delayed_work include/linux/workqueue.h:509 [inline] srcu_reschedule kernel/rcu/srcutree.c:1226 [inline] srcu_reschedule+0xd7/0x130 kernel/rcu/srcutree.c:1209 process_srcu+0x125/0xe10 kernel/rcu/srcutree.c:1239 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 10138: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3623 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x68/0x100 mm/util.c:574 kvmalloc include/linux/mm.h:645 [inline] kvzalloc include/linux/mm.h:653 [inline] alloc_netdev_mqs+0x98/0xe40 net/core/dev.c:9797 vti6_init_net+0x244/0x810 net/ipv6/ip6_vti.c:1119 ops_init+0xb3/0x420 net/core/net_namespace.c:137 setup_net+0x2d5/0x8b0 net/core/net_namespace.c:327 copy_net_ns+0x29e/0x5a0 net/core/net_namespace.c:468 create_new_namespaces+0x403/0xb50 kernel/nsproxy.c:108 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:229 ksys_unshare+0x444/0x980 kernel/fork.c:2955 __do_sys_unshare kernel/fork.c:3023 [inline] __se_sys_unshare kernel/fork.c:3021 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3021 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 13476: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 __netdev_name_node_alt_destroy+0x1ff/0x2a0 net/core/dev.c:322 netdev_name_node_alt_destroy+0x57/0x80 net/core/dev.c:334 rtnl_alt_ifname net/core/rtnetlink.c:3518 [inline] rtnl_linkprop.isra.0+0x575/0x6f0 net/core/rtnetlink.c:3567 rtnl_dellinkprop+0x46/0x60 net/core/rtnetlink.c:3588 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88805b93e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1416 bytes inside of 4096-byte region [ffff88805b93e000, ffff88805b93f000) The buggy address belongs to the page: page:ffffea00016e4f80 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00016e4608 ffffea00016e5908 ffff8880aa402000 raw: 0000000000000000 ffff88805b93e000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805b93e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805b93e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805b93e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805b93e600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805b93e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================