syzbot

==================================================================
BUG: KASAN: slab-out-of-bounds in fib6_info_nh_dev include/net/nexthop.h:536 [inline]
BUG: KASAN: slab-out-of-bounds in nft_fib6_info_nh_uses_dev net/ipv6/netfilter/nft_fib_ipv6.c:174 [inline]
BUG: KASAN: slab-out-of-bounds in nft_fib6_eval+0x1673/0x17e0 net/ipv6/netfilter/nft_fib_ipv6.c:231
Read of size 8 at addr ffff88803f4b12d0 by task syz.2.1268/10672

CPU: 0 UID: 0 PID: 10672 Comm: syz.2.1268 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595
 fib6_info_nh_dev include/net/nexthop.h:536 [inline]
 nft_fib6_info_nh_uses_dev net/ipv6/netfilter/nft_fib_ipv6.c:174 [inline]
 nft_fib6_eval+0x1673/0x17e0 net/ipv6/netfilter/nft_fib_ipv6.c:231
 nft_fib_inet_eval+0x200/0x250 net/netfilter/nft_fib_inet.c:34
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x2e5/0x1990 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
 NF_HOOK include/linux/netfilter.h:316 [inline]
 ipv6_rcv+0xa4/0x3d0 net/ipv6/ip6_input.c:351
 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6202
 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6315
 netif_receive_skb_internal net/core/dev.c:6401 [inline]
 netif_receive_skb+0x13b/0x7f0 net/core/dev.c:6460
 tun_rx_batched.isra.0+0x3f6/0x750 drivers/net/tun.c:1511
 tun_get_user+0x1e31/0x3c20 drivers/net/tun.c:1955
 tun_chr_write_iter+0xdc/0x200 drivers/net/tun.c:2001
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:688
 ksys_write+0x12a/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f86bb95d68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f86b9bf5fb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f86b9bf66c0 RCX: 00007f86bb95d68e
RDX: 0000000000000086 RSI: 0000200000000600 RDI: 00000000000000c8
RBP: 00007f86bba32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f86bbc16038 R14: 00007f86bbc15fa0 R15: 00007ffda61ded38
 </TASK>

Allocated by task 7920:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 nexthop_alloc+0x3c/0x1f0 net/ipv4/nexthop.c:536
 nexthop_create net/ipv4/nexthop.c:2918 [inline]
 nexthop_add net/ipv4/nexthop.c:2985 [inline]
 rtm_new_nexthop+0x1e8b/0x8760 net/ipv4/nexthop.c:3299
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6996
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
 __sys_sendmsg+0x170/0x220 net/socket.c:2784
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803f4b1200
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 8 bytes to the right of
 allocated 200-byte region [ffff88803f4b1200, ffff88803f4b12c8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3f4b0
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b842b40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b842b40 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
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 5738, tgid 5738 (syz-executor), ts 63856485410, free_ts 63593545241
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab mm/slub.c:3467 [inline]
 new_slab+0xa6/0x6c0 mm/slub.c:3525
 refill_objects+0x277/0x420 mm/slub.c:7271
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __do_kmalloc_node mm/slub.c:5294 [inline]
 __kmalloc_noprof+0x688/0x850 mm/slub.c:5307
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 fib_create_info+0x5bf/0x4640 net/ipv4/fib_semantics.c:1400
 fib_table_insert+0x169/0x1c70 net/ipv4/fib_trie.c:1212
 fib_magic+0x4d4/0x5c0 net/ipv4/fib_frontend.c:1134
 fib_add_ifaddr+0x16d/0x560 net/ipv4/fib_frontend.c:1156
 fib_inetaddr_event+0x147/0x270 net/ipv4/fib_frontend.c:1470
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 blocking_notifier_call_chain kernel/notifier.c:380 [inline]
 blocking_notifier_call_chain+0x69/0xa0 kernel/notifier.c:368
 __inet_insert_ifa+0x91d/0xc70 net/ipv4/devinet.c:566
 inet_rtm_newaddr+0xea1/0x18b0 net/ipv4/devinet.c:1001
page last free pid 5733 tgid 5733 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 __do_kmalloc_node mm/slub.c:5294 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5407
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 kstrdup_const+0x63/0x80 mm/util.c:104
 __kernfs_new_node+0x9b/0x9f0 fs/kernfs/dir.c:660
 kernfs_new_node+0x11b/0x1a0 fs/kernfs/dir.c:748
 kernfs_create_link+0xcc/0x240 fs/kernfs/symlink.c:39
 sysfs_do_create_link_sd+0x90/0x140 fs/sysfs/symlink.c:44
 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline]
 sysfs_create_link+0x61/0xc0 fs/sysfs/symlink.c:92
 driver_sysfs_add+0x91/0x2d0 drivers/base/dd.c:490
 really_probe+0x146/0xa60 drivers/base/dd.c:697
 __driver_probe_device+0x22e/0x480 drivers/base/dd.c:871
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:901

Memory state around the buggy address:
 ffff88803f4b1180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803f4b1200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88803f4b1280: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
                                                 ^
 ffff88803f4b1300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803f4b1380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================