================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] BUG: KASAN: use-after-free in ip6mr_sk_done+0x139/0x400 net/ipv6/ip6mr.c:1604 Read of size 4 at addr ffff888077e25688 by task syz-executor.2/21830 CPU: 1 PID: 21830 Comm: syz-executor.2 Not tainted 6.0.0-rc7-syzkaller-00239-gb357fd1c2afc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 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:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] ip6mr_sk_done+0x139/0x400 net/ipv6/ip6mr.c:1604 rawv6_close+0x58/0x80 net/ipv6/raw.c:1167 inet_release+0x12e/0x270 net/ipv4/af_inet.c:428 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:482 __sock_release net/socket.c:650 [inline] sock_release+0x87/0x1b0 net/socket.c:678 inet_ctl_sock_destroy include/net/inet_common.h:71 [inline] igmp6_net_exit+0x6b/0x170 net/ipv6/mcast.c:3167 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 setup_net+0x7fb/0xc50 net/core/net_namespace.c:348 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:3181 __do_sys_unshare kernel/fork.c:3252 [inline] __se_sys_unshare kernel/fork.c:3250 [inline] __ia32_sys_unshare+0x2c/0x40 kernel/fork.c:3250 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 RIP: 0023:0xf7fdf549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f7fda5cc EFLAGS: 00000296 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 0000000040000400 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 21830: 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:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmemdup+0x23/0x50 mm/util.c:129 kmemdup include/linux/fortify-string.h:456 [inline] addrconf_init_net+0x1be/0x870 net/ipv6/addrconf.c:7161 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:3181 __do_sys_unshare kernel/fork.c:3252 [inline] __se_sys_unshare kernel/fork.c:3250 [inline] __ia32_sys_unshare+0x2c/0x40 kernel/fork.c:3250 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 21830: 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:367 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1759 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1785 slab_free mm/slub.c:3539 [inline] kfree+0xe2/0x580 mm/slub.c:4567 addrconf_init_net+0x649/0x870 net/ipv6/addrconf.c:7219 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:3181 __do_sys_unshare kernel/fork.c:3252 [inline] __se_sys_unshare kernel/fork.c:3250 [inline] __ia32_sys_unshare+0x2c/0x40 kernel/fork.c:3250 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 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 kvfree_call_rcu+0x74/0x940 kernel/rcu/tree.c:3322 drop_sysctl_table+0x3c0/0x4e0 fs/proc/proc_sysctl.c:1716 unregister_sysctl_table fs/proc/proc_sysctl.c:1754 [inline] unregister_sysctl_table+0xc0/0x190 fs/proc/proc_sysctl.c:1729 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7112 [inline] addrconf_exit_net+0x9d/0x3f0 net/ipv6/addrconf.c:7231 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x991/0x1610 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 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 kvfree_call_rcu+0x74/0x940 kernel/rcu/tree.c:3322 drop_sysctl_table+0x3c0/0x4e0 fs/proc/proc_sysctl.c:1716 unregister_sysctl_table fs/proc/proc_sysctl.c:1754 [inline] unregister_sysctl_table+0xc0/0x190 fs/proc/proc_sysctl.c:1729 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7112 [inline] addrconf_sysctl_unregister+0xee/0x1c0 net/ipv6/addrconf.c:7140 addrconf_ifdown.isra.0+0x128c/0x1830 net/ipv6/addrconf.c:3903 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] unregister_netdevice_many+0xa62/0x1980 net/core/dev.c:10862 default_device_exit_batch+0x449/0x590 net/core/dev.c:11356 ops_exit_list+0x125/0x170 net/core/net_namespace.c:167 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x991/0x1610 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 ffff888077e25600 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 136 bytes inside of 256-byte region [ffff888077e25600, ffff888077e25700) The buggy address belongs to the physical page: page:ffffea0001df8900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77e24 head:ffffea0001df8900 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888011841b40 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3667, tgid 3667 (syz-executor.1), ts 144995542531, free_ts 144989420526 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5549 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1829 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x7f1/0xe10 mm/slub.c:3036 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123 slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] __kmalloc+0x32b/0x340 mm/slub.c:4425 kmalloc include/linux/slab.h:605 [inline] kzalloc include/linux/slab.h:733 [inline] fib_create_info+0xdbe/0x4ac0 net/ipv4/fib_semantics.c:1449 fib_table_insert+0x195/0x1be0 net/ipv4/fib_trie.c:1236 fib_magic+0x455/0x540 net/ipv4/fib_frontend.c:1098 fib_add_ifaddr+0x389/0x540 net/ipv4/fib_frontend.c:1135 fib_netdev_event+0x462/0x680 net/ipv4/fib_frontend.c:1480 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] __dev_notify_flags+0x110/0x2b0 net/core/dev.c:8594 dev_change_flags+0x112/0x170 net/core/dev.c:8632 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 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:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3248 [inline] slab_alloc mm/slub.c:3256 [inline] kmem_cache_alloc_trace+0x2c0/0x3e0 mm/slub.c:3287 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] ref_tracker_alloc+0x14c/0x550 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:3974 [inline] netdev_hold include/linux/netdevice.h:4003 [inline] netdev_hold include/linux/netdevice.h:3998 [inline] netdev_queue_add_kobject net/core/net-sysfs.c:1663 [inline] netdev_queue_update_kobjects+0x1a7/0x4e0 net/core/net-sysfs.c:1718 register_queue_kobjects net/core/net-sysfs.c:1779 [inline] netdev_register_kobject+0x330/0x400 net/core/net-sysfs.c:2019 register_netdevice+0xe01/0x1680 net/core/dev.c:10070 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x3c3/0x520 drivers/net/netdevsim/netdev.c:365 __nsim_dev_port_add+0x2bb/0x880 drivers/net/netdevsim/dev.c:1379 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1437 [inline] nsim_drv_probe+0xd80/0x1310 drivers/net/netdevsim/dev.c:1591 call_driver_probe drivers/base/dd.c:560 [inline] really_probe+0x249/0xb90 drivers/base/dd.c:639 __driver_probe_device+0x1df/0x4d0 drivers/base/dd.c:778 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:808 Memory state around the buggy address: ffff888077e25580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888077e25600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888077e25680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077e25700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888077e25780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi