syzbot

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BUG: KASAN: slab-out-of-bounds in tipc_nametbl_lookup_dst_nodes+0x44c/0x4c0 net/tipc/name_table.c:670
Read of size 4 at addr ffff8880a4ebacd0 by task syz-executor219/7985

CPU: 0 PID: 7985 Comm: syz-executor219 Not tainted 4.14.300-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load4_noabort+0x68/0x70 mm/kasan/report.c:429
 tipc_nametbl_lookup_dst_nodes+0x44c/0x4c0 net/tipc/name_table.c:670
 tipc_sendmcast+0x51a/0xac0 net/tipc/socket.c:768
 __tipc_sendmsg+0xbab/0xf90 net/tipc/socket.c:975
 tipc_sendmsg+0x4c/0x70 net/tipc/socket.c:923
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3

Allocated by task 1:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 tipc_nameseq_create+0x53/0x290 net/tipc/name_table.c:152
 tipc_nametbl_insert_publ+0xb37/0x14e0 net/tipc/name_table.c:476
 tipc_nametbl_publish+0x211/0x3f0 net/tipc/name_table.c:701
 tipc_sk_publish net/tipc/socket.c:2206 [inline]
 tipc_bind+0x2c4/0x600 net/tipc/socket.c:630
 tipc_create_listen_sock net/tipc/server.c:338 [inline]
 tipc_open_listening_sock net/tipc/server.c:396 [inline]
 tipc_server_start+0x31f/0x880 net/tipc/server.c:611
 tipc_topsrv_start net/tipc/subscr.c:382 [inline]
 tipc_topsrv_init_net+0x53b/0x730 net/tipc/subscr.c:397
 ops_init+0xaa/0x3e0 net/core/net_namespace.c:118
 __register_pernet_operations net/core/net_namespace.c:885 [inline]
 register_pernet_operations+0x32f/0x750 net/core/net_namespace.c:959
 register_pernet_device+0x28/0x70 net/core/net_namespace.c:1047
 tipc_init+0x7d/0x137 net/tipc/core.c:136
 do_one_initcall+0x88/0x210 init/main.c:830
 do_initcall_level init/main.c:896 [inline]
 do_initcalls init/main.c:904 [inline]
 do_basic_setup init/main.c:922 [inline]
 kernel_init_freeable+0x565/0x626 init/main.c:1081
 kernel_init+0xd/0x167 init/main.c:1006
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880a4ebacc0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 16 bytes inside of
 32-byte region [ffff8880a4ebacc0, ffff8880a4ebace0)
The buggy address belongs to the page:
page:ffffea000293ae80 count:1 mapcount:0 mapping:ffff8880a4eba000 index:0xffff8880a4ebafc1
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff8880a4eba000 ffff8880a4ebafc1 0000000100000029
raw: ffffea0002919aa0 ffffea0002931ba0 ffff88813fe741c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a4ebab80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8880a4ebac00: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc
>ffff8880a4ebac80: 04 fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
                                                 ^
 ffff8880a4ebad00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8880a4ebad80: 00 00 00 fc fc fc fc fc 00 00 fc fc fc fc fc fc
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