Description of problem:
Disconnected a micro-sd card reader

Additional info:
reporter:       libreport-2.2.2
BUG: soft lockup - CPU#0 stuck for 23s! [systemd-udevd:2039]
Modules linked in: uas usb_storage bnep bluetooth fuse xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack tun bridge stp llc ccm iTCO_wdt iTCO_vendor_support vfat fat x86_pkg_temp_thermal coretemp kvm_intel arc4 kvm rt2800pci rt2800mmio rt2800lib rt2x00pci rt2x00mmio rt2x00lib eeprom_93cx6 mac80211 snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel crct10dif_pclmul snd_hda_controller crc32_pclmul cfg80211 snd_hda_codec crc32c_intel snd_hwdep ghash_clmulni_intel snd_seq joydev snd_seq_device snd_pcm microcode crc_ccitt rfkill serio_raw i2c_i801 snd_timer mei_me lpc_ich snd mei mfd_core soundcore tpm_tis tpm_infineon video shpchp tpm sunrpc radeon i2c_algo_bit drm_kms_helper ttm e1000e drm ptp i2c_core pps_core
CPU: 0 PID: 2039 Comm: systemd-udevd Not tainted 3.15.0-0.rc5.git2.10.fc21.x86_64 #1
Hardware name: Gigabyte Technology Co., Ltd. Z87-D3HP/Z87-D3HP-CF, BIOS F5c 06/19/2013
task: ffff8803fe3ec4b0 ti: ffff8803a6eaa000 task.ti: ffff8803a6eaa000
RIP: 0010:[<ffffffff813739f3>]  [<ffffffff813739f3>] __list_add+0x43/0xd0
RSP: 0018:ffff8803a6eabba8  EFLAGS: 00000287
RAX: ffff880092dd1a80 RBX: ffff88043ec18150 RCX: 00000000b178b177
RDX: ffff88037c464500 RSI: ffff8803a6eabc10 RDI: ffff880092dd1b00
RBP: ffff8803a6eabba8 R08: ffff88037c464500 R09: 0000000180240023
R10: ffff88043ec18150 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8803a6eabb98 R14: ffff88040adf3460 R15: ffff88042e04ae00
FS:  00007f7e8f99d880(0000) GS:ffff88043ec00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7e918f2d30 CR3: 00000003f5dce000 CR4: 00000000001407f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8803a6eabbc8 ffffffff81205d2d ffff880092dd1b00 ffff880092dd1a80
 ffff8803a6eabbf8 ffffffff81206f23 ffff8803a6eabc10 ffff88037b290900
 0000000000000025 ffff8803a6eabe50 ffff8803a6eabc48 ffffffff812071bc
Call Trace:
 [<ffffffff81205d2d>] d_shrink_add+0x2d/0x70
 [<ffffffff81206f23>] shrink_dentry_list+0x113/0x120
 [<ffffffff812071bc>] check_submounts_and_drop+0x7c/0xb0
 [<ffffffff8126a42d>] kernfs_dop_revalidate+0x5d/0xd0
 [<ffffffff811f9a46>] lookup_fast+0x276/0x2f0
 [<ffffffff812efdcc>] ? security_inode_permission+0x1c/0x30
 [<ffffffff811fab97>] link_path_walk+0x1d7/0xec0
 [<ffffffff8118631c>] ? lru_cache_add+0x1c/0x50
 [<ffffffff811fb8e7>] path_lookupat+0x67/0xd70
 [<ffffffff811a577d>] ? handle_mm_fault+0x93d/0x10f0
 [<ffffffff811fc61a>] filename_lookup+0x2a/0xd0
 [<ffffffff81200a67>] user_path_at_empty+0x67/0xd0
 [<ffffffff811f444b>] SyS_readlink+0x5b/0x130
 [<ffffffff81710ce9>] system_call_fastpath+0x16/0x1b
Code: f0 75 2d 4d 8b 45 00 4d 39 c4 75 54 4c 39 e3 74 77 4c 39 eb 74 72 49 89 5c 24 08 4c 89 23 4c 89 6b 08 49 89 5d 00 5b 41 5c 41 5d <5d> c3 0f 1f 00 49 89 d1 48 89 f1 31 c0 48 c7 c2 a0 6a a5 81 be