WARNING in sysfs_do_create_link_sd

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 8bac5040 Linux 4.14.167
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12e58479e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ed52db44a31a52da
dashboard link: https://syzkaller.appspot.com/bug?extid=31ea7e282ccf9fadd181
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+31ea7e...@syzkaller.appspotmail.com

should_failslab+0xdb/0x130 mm/failslab.c:32
slab_pre_alloc_hook mm/slab.h:421 [inline]
slab_alloc_node mm/slab.c:3297 [inline]
kmem_cache_alloc_node_trace+0x280/0x770 mm/slab.c:3659
__do_kmalloc_node mm/slab.c:3681 [inline]
__kmalloc_node_track_caller+0x3d/0x80 mm/slab.c:3696
------------[ cut here ]------------
__kmalloc_reserve.isra.0+0x40/0xe0 net/core/skbuff.c:137
WARNING: CPU: 1 PID: 20959 at fs/sysfs/dir.c:30 sysfs_warn_dup.cold+0x17/0x31 fs/sysfs/dir.c:30
Kernel panic - not syncing: panic_on_warn set ...

__alloc_skb+0xcf/0x500 net/core/skbuff.c:205
alloc_skb include/linux/skbuff.h:980 [inline]
alloc_skb_with_frags+0x86/0x4b0 net/core/skbuff.c:5228
sock_alloc_send_pskb+0x5db/0x740 net/core/sock.c:2078
sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2095
__ip_append_data.isra.0+0x1227/0x20f0 net/ipv4/ip_output.c:972
ip_make_skb+0x17a/0x1d0 net/ipv4/ip_output.c:1489
udp_sendmsg+0x16a6/0x1da0 net/ipv4/udp.c:1052
udpv6_sendmsg+0x1393/0x2610 net/ipv6/udp.c:1193
inet_sendmsg+0x122/0x500 net/ipv4/af_inet.c:762
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xce/0x110 net/socket.c:656
___sys_sendmsg+0x349/0x840 net/socket.c:2062
__sys_sendmmsg+0x152/0x3a0 net/socket.c:2152
SYSC_sendmmsg net/socket.c:2183 [inline]
SyS_sendmmsg+0x35/0x60 net/socket.c:2178
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45b349
RSP: 002b:00007f7b95786c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f7b957876d4 RCX: 000000000045b349
RDX: 00000000000004ff RSI: 00000000200092c0 RDI: 0000000000000007
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 00000000000008a7 R14: 00000000004ca021 R15: 0000000000000033
CPU: 1 PID: 20959 Comm: syz-executor.2 Not tainted 4.14.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x142/0x197 lib/dump_stack.c:58
panic+0x1f9/0x42d kernel/panic.c:183
__warn.cold+0x2f/0x2f kernel/panic.c:547
report_bug+0x216/0x254 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:sysfs_warn_dup.cold+0x17/0x31 fs/sysfs/dir.c:30
RSP: 0018:ffff8881f02a7220 EFLAGS: 00010286
RAX: 000000000000003c RBX: ffffffffffffffef RCX: 0000000000000000
RDX: 000000000001238f RSI: ffffffff814b6655 RDI: ffffed103e054e3a
RBP: ffff8881f02a7238 R08: 000000000000003c R09: ffff88804b144b30
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881d37bac80
R13: ffff8880a7d52700 R14: ffff8880a87b5d00 R15: 0000000000000001
sysfs_do_create_link_sd.isra.0+0xff/0x120 fs/sysfs/symlink.c:51
sysfs_do_create_link fs/sysfs/symlink.c:80 [inline]
sysfs_create_link+0x65/0xc0 fs/sysfs/symlink.c:92
device_add_class_symlinks drivers/base/core.c:1673 [inline]
device_add+0x735/0x1490 drivers/base/core.c:1875
wiphy_register+0x133c/0x1d20 net/wireless/core.c:809
ieee80211_register_hw+0x1152/0x2f30 net/mac80211/main.c:1055
mac80211_hwsim_new_radio+0x19a1/0x2980 drivers/net/wireless/mac80211_hwsim.c:2705
hwsim_new_radio_nl+0x3f2/0x62e drivers/net/wireless/mac80211_hwsim.c:3164
genl_family_rcv_msg+0x614/0xc30 net/netlink/genetlink.c:600
genl_rcv_msg+0xb4/0x150 net/netlink/genetlink.c:625
netlink_rcv_skb+0x14f/0x3c0 net/netlink/af_netlink.c:2432
genl_rcv+0x29/0x40 net/netlink/genetlink.c:636
netlink_unicast_kernel net/netlink/af_netlink.c:1286 [inline]
netlink_unicast+0x44d/0x650 net/netlink/af_netlink.c:1312
netlink_sendmsg+0x7c4/0xc60 net/netlink/af_netlink.c:1877
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xce/0x110 net/socket.c:656
___sys_sendmsg+0x70a/0x840 net/socket.c:2062
__sys_sendmsg+0xb9/0x140 net/socket.c:2096
SYSC_sendmsg net/socket.c:2107 [inline]
SyS_sendmsg+0x2d/0x50 net/socket.c:2103
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45b349
RSP: 002b:00007fc452f07c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc452f086d4 RCX: 000000000045b349
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000006
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000997 R14: 00000000004cb0df R15: 000000000075bfd4
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.