Bluetooth: Fix possible NULL pointer dereference

Backport of the upstreamed and not merged patch [1].
It fixes the crash like [2].

If we disconnect a device before completing the connection, connection
will no longer be available in connection list, thus conn will be NULL.

[1] https://www.spinics.net/lists/linux-bluetooth/msg70764.html
[2]
[ 4960.112410] Unable to handle kernel NULL pointer dereference at virtual address 0000001a
[ 4961.120795] Mem abort info:
[ 4961.128933]   Exception class = DABT (current EL), IL = 32 bits
[ 4961.140189]   SET = 0, FnV = 0
[ 4961.148719]   EA = 0, S1PTW = 0
[ 4961.157065] Data abort info:
[ 4961.165047]   ISV = 0, ISS = 0x00000004
[ 4961.173975]   CM = 0, WnR = 0
[ 4961.181934] user pgtable: 4k pages, 48-bit VAs, pgd = ffff80084f467000
[ 4961.193579] [000000000000001a] *pgd=0000000000000000
[ 4961.201942] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 4961.210271] Modules linked in: veth xt_nat xt_tcpudp ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype iptable_filter ip_tables xt_conntrack x_tables nf_nat nf_conntrack libcrc32c br_netfilter bridge stp overlay crc32_ce crct10dif_ce mwifiex_pcie mwifiex cdc_acm galcore(O)
[ 4961.255701] Process kworker/u13:0 (pid: 12632, stack limit = 0xffff00002e5e8000)
[ 4961.268662] CPU: 3 PID: 12632 Comm: kworker/u13:0 Tainted: G           O    4.14.159-4.0.0-devel+git.fff496c2a1bd #1
[ 4961.284881] Hardware name: Toradex Apalis iMX8QM/QP on Apalis Evaluation Board (DT)
[ 4961.298330] Workqueue: hci0 hci_rx_work
[ 4961.307903] task: ffff80084faa8d80 task.stack: ffff00002e5e8000
[ 4961.319611] PC is at hci_connect_le_scan_cleanup+0x14/0x128
[ 4961.330986] LR is at create_le_conn_complete+0xec/0x108

Signed-off-by: Thomas Gagneret <tgagneret@xxxxxxxxxxx>
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>

0 files changed, 0 insertions, 0 deletions