================================================================== BUG: KASAN: use-after-free in inet_frag_destroy_rcu+0xd9/0xe0 net/ipv4/inet_fragment.c:201 Read of size 8 at addr ffff88804e94a358 by task syz-executor.3/7162 CPU: 0 PID: 7162 Comm: syz-executor.3 Not tainted 5.2.0-rc2-next-20190529 #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 inet_frag_destroy_rcu+0xd9/0xe0 net/ipv4/inet_fragment.c:201 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2092 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2310 [inline] rcu_core+0xba5/0x1500 kernel/rcu/tree.c:2291 __do_softirq+0x25c/0x94c kernel/softirq.c:293 invoke_softirq kernel/softirq.c:374 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:414 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline] RIP: 0010:console_unlock+0xb7c/0xec0 kernel/printk/printk.c:2471 Code: d2 88 48 c1 e8 03 42 80 3c 30 00 0f 85 e4 02 00 00 48 83 3d 35 dd 77 07 00 0f 84 91 01 00 00 e8 2a 45 16 00 48 8b 7d 98 57 9d <0f> 1f 44 00 00 e9 6d ff ff ff e8 15 45 16 00 48 8b 7d 08 c7 05 57 RSP: 0018:ffff888043206bb8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff888036eb22c0 RBX: 0000000000000200 RCX: 1ffff11006dd6572 RDX: 0000000000000000 RSI: ffffffff815a9746 RDI: 0000000000000293 RBP: ffff888043206c40 R08: ffff888036eb22c0 R09: ffff888036eb2b90 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff84290640 R14: dffffc0000000000 R15: ffffffff893a6350 vprintk_emit+0x2a0/0x700 kernel/printk/printk.c:1986 vprintk_default+0x28/0x30 kernel/printk/printk.c:2013 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:386 printk+0xba/0xed kernel/printk/printk.c:2046 vlan_device_event.cold+0x1b/0x2f net/8021q/vlan.c:389 notifier_call_chain+0xc2/0x230 kernel/notifier.c:95 __raw_notifier_call_chain kernel/notifier.c:396 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:403 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1753 call_netdevice_notifiers_extack net/core/dev.c:1765 [inline] call_netdevice_notifiers net/core/dev.c:1779 [inline] __dev_notify_flags+0x121/0x2c0 net/core/dev.c:7626 dev_change_flags+0x10d/0x170 net/core/dev.c:7664 do_setlink+0x1615/0x34e0 net/core/rtnetlink.c:2492 __rtnl_newlink+0xbd8/0x16c0 net/core/rtnetlink.c:3124 rtnl_newlink+0x69/0xa0 net/core/rtnetlink.c:3249 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5218 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2486 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5236 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1337 netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1926 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:671 __sys_sendto+0x262/0x380 net/socket.c:1964 __do_sys_sendto net/socket.c:1976 [inline] __se_sys_sendto net/socket.c:1972 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1972 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4130c3 Code: ff 0f 83 b0 19 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d cd 31 66 00 00 75 17 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 81 19 00 00 c3 48 83 ec 08 e8 87 fa ff ff RSP: 002b:00007ffe07a76eb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004130c3 RDX: 0000000000000038 RSI: 0000000000a70070 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffe07a76ec0 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 0000000000000003 R14: 00007ffe07a76f68 R15: 0000000000000006 Allocated by task 8939: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 kmem_cache_alloc_trace+0x151/0x750 mm/slab.c:3555 kmalloc include/linux/slab.h:547 [inline] kzalloc include/linux/slab.h:742 [inline] fqdir_init include/net/inet_frag.h:115 [inline] nf_ct_net_init+0x4a/0x4d0 net/ipv6/netfilter/nf_conntrack_reasm.c:492 ops_init+0xb3/0x410 net/core/net_namespace.c:130 setup_net+0x2d3/0x740 net/core/net_namespace.c:316 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:439 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2719 __do_sys_unshare kernel/fork.c:2787 [inline] __se_sys_unshare kernel/fork.c:2785 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2785 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 7101: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kfree+0xcf/0x220 mm/slab.c:3755 fqdir_rwork_fn+0x33/0x40 net/ipv4/inet_fragment.c:154 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff88804e94a340 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of 512-byte region [ffff88804e94a340, ffff88804e94a540) The buggy address belongs to the page: page:ffffea00013a5280 refcount:1 mapcount:0 mapping:ffff8880aa400940 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00012f4b48 ffffea00012fe4c8 ffff8880aa400940 raw: 0000000000000000 ffff88804e94a0c0 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88804e94a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804e94a280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88804e94a300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff88804e94a380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804e94a400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================