oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=syz5,mems_allowed=0-1,oom_memcg=/syz5,task_memcg=/syz5,task=syz-executor.5,pid=5849,uid=0
Memory cgroup out of memory: Killed process 5849 (syz-executor.5) total-vm:50620kB, anon-rss:464kB, file-rss:9064kB, shmem-rss:64kB, UID:0 pgtables:72kB oom_score_adj:0
==================================================================
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 ffff888026ccd288 by task syz-executor.5/7933

CPU: 0 PID: 7933 Comm: syz-executor.5 Not tainted 6.0.0-syzkaller-02744-g2e30960097f6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
 <TASK>
 __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
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x304d/0x7090 kernel/fork.c:2257
 kernel_clone+0xe7/0xab0 kernel/fork.c:2671
 __do_sys_clone+0xba/0x100 kernel/fork.c:2805
 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
RIP: 0033:0x7f28e128a5a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f28e2456118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f28e13ac050 RCX: 00007f28e128a5a9
RDX: 0000000020000380 RSI: 0000000020000310 RDI: 0000000042300400
RBP: 00007f28e12e5580 R08: 0000000020000400 R09: 0000000020000400
R10: 00000000200003c0 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffdc22c650f R14: 00007f28e2456300 R15: 0000000000022000
 </TASK>

Allocated by task 7933:
 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:565 [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
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x304d/0x7090 kernel/fork.c:2257
 kernel_clone+0xe7/0xab0 kernel/fork.c:2671
 __do_sys_clone+0xba/0x100 kernel/fork.c:2805
 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

Freed by task 7933:
 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
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x304d/0x7090 kernel/fork.c:2257
 kernel_clone+0xe7/0xab0 kernel/fork.c:2671
 __do_sys_clone+0xba/0x100 kernel/fork.c:2805
 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

The buggy address belongs to the object at ffff888026ccd200
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 136 bytes inside of
 256-byte region [ffff888026ccd200, ffff888026ccd300)

The buggy address belongs to the physical page:
page:ffffea00009b3300 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26ccc
head:ffffea00009b3300 order:1 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 7933, tgid 7931 (syz-executor.5), ts 447219754309, free_ts 433500196175
 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+0x84f/0xe80 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_track_caller+0x325/0x340 mm/slub.c:4931
 kmemdup+0x23/0x50 mm/util.c:129
 kmemdup include/linux/fortify-string.h:565 [inline]
 ip6_route_net_init+0x215/0x8c0 net/ipv6/route.c:6490
 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
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x304d/0x7090 kernel/fork.c:2257
 kernel_clone+0xe7/0xab0 kernel/fork.c:2671
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]
 kmem_cache_alloc_node+0x2b1/0x3f0 mm/slub.c:3298
 __alloc_skb+0x210/0x2f0 net/core/skbuff.c:497
 alloc_skb include/linux/skbuff.h:1265 [inline]
 nlmsg_new include/net/netlink.h:964 [inline]
 inet_netconf_notify_devconf+0xdd/0x260 net/ipv4/devinet.c:2101
 __devinet_sysctl_unregister net/ipv4/devinet.c:2613 [inline]
 devinet_exit_net+0x10f/0x280 net/ipv4/devinet.c:2752
 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
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x304d/0x7090 kernel/fork.c:2257
 kernel_clone+0xe7/0xab0 kernel/fork.c:2671

Memory state around the buggy address:
 ffff888026ccd180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888026ccd200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888026ccd280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888026ccd300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888026ccd380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================