verification for focal:
$ nproc: 24

Current machine settings before using -proposed:

1. $uname -r: 5.4.0-192-generic

2. sudo dmesg | grep bnx2x :

[    5.636662] bnx2x: QLogic 5771x/578xx 10/20-Gigabit Ethernet Driver bnx2x 1.713.36-0 (2014/02/10)
[    5.735751] bnx2x 0000:04:00.0: msix capability found
[    5.750740] bnx2x 0000:04:00.0: part number 0-0-0-0
[    6.135089] bnx2x 0000:04:00.0: 32.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x8 link)
[    6.160661] bnx2x 0000:04:00.1: msix capability found
[    6.199296] bnx2x 0000:04:00.1: part number 0-0-0-0
[    6.872498] bnx2x 0000:04:00.1: 32.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x8 link)
[    7.002297] bnx2x 0000:04:00.1 eno50: renamed from eth0
[    7.045651] bnx2x 0000:04:00.0 eno49: renamed from eth3

3. We can see that there are two interfaces on this machine utilizing the bnx2x driver. As noted in the description increasing the num_queue variable value will not result in any UBSAN warnings since 5.4 has them disabled: 
$ sudo modprobe -r bnx2x # remove the driver
$ sudo modprobe bnx2x num_queues=20 # reload the driver while exceeding the 15 queue size limit
$ sudo dmesg | grep bnx2x 
...<cut output>...
[ 1916.385403] bnx2x: QLogic 5771x/578xx 10/20-Gigabit Ethernet Driver bnx2x 1.713.36-0 (2014/02/10)
[ 1916.385657] bnx2x 0000:04:00.0: msix capability found
[ 1916.405826] bnx2x 0000:04:00.0: part number 0-0-0-0
[ 1916.571785] bnx2x 0000:04:00.0: 32.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x8 link)
[ 1916.571889] bnx2x 0000:04:00.1: msix capability found
[ 1916.576504] bnx2x 0000:04:00.0 eno49: renamed from eth0
[ 1916.589777] bnx2x 0000:04:00.1: part number 0-0-0-0
[ 1917.291516] bnx2x 0000:04:00.0 eno49: using MSI-X  IRQs: sp 67  fp[0] 69 ... fp[19] 118
[ 1918.062391] bnx2x 0000:04:00.1: 32.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x8 link)
[ 1918.064708] bnx2x 0000:04:00.1 eno50: renamed from eth0
[ 1918.711960] bnx2x 0000:04:00.1 eno50: using MSI-X  IRQs: sp 119  fp[0] 121 ... fp[19] 140
[ 1925.737490] bnx2x 0000:04:00.0 eno49: NIC Link is Up, 10000 Mbps full duplex, Flow control: none
[ 1926.017458] bnx2x 0000:04:00.1 eno50: NIC Link is Up, 10000 Mbps full duplex, Flow control: none

$ sudo dmesg | grep UBSAN
<no result>
4. We know that the machine is accessing data out of bounds but the kernel is not reporting it. Let's upgrade to -proposed and see if the machine remains stable.

After upgrading to -proposed:

1. $uname -r: 5.4.0-195-generic

2. sudo dmesg | grep bnx2x :

[    5.506585] bnx2x: QLogic 5771x/578xx 10/20-Gigabit Ethernet Driver bnx2x 1.713.36-0 (2014/02/10)
[    5.558991] bnx2x 0000:04:00.0: msix capability found
[    5.574191] bnx2x 0000:04:00.0: part number 0-0-0-0
[    5.987916] bnx2x 0000:04:00.0: 32.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x8 link)
[    6.009746] bnx2x 0000:04:00.1: msix capability found
[    6.056350] bnx2x 0000:04:00.1: part number 0-0-0-0
[    6.751651] bnx2x 0000:04:00.1: 32.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x8 link)
[    6.885873] bnx2x 0000:04:00.0 eno49: renamed from eth2
[    6.929575] bnx2x 0000:04:00.1 eno50: renamed from eth0
[   19.510740] bnx2x 0000:04:00.1 eno50: using MSI-X  IRQs: sp 77  fp[0] 79 ... fp[7] 86
[   20.986392] bnx2x 0000:04:00.0 eno49: using MSI-X  IRQs: sp 67  fp[0] 69 ... fp[7] 76
[   28.077341] bnx2x 0000:04:00.0 eno49: NIC Link is Up, 10000 Mbps full duplex, Flow control: none
[   28.129317] bnx2x 0000:04:00.1 eno50: NIC Link is Up, 10000 Mbps full duplex, Flow control: none

3. sudo modprobe -r bnx2x 
4. sudo modprobe bnx2x num_queues=20 

[  319.495823] bnx2x: QLogic 5771x/578xx 10/20-Gigabit Ethernet Driver bnx2x 1.713.36-0 (2014/02/10)
[  319.495993] bnx2x 0000:04:00.0: msix capability found
[  319.512977] bnx2x 0000:04:00.0: part number 0-0-0-0
[  319.680625] bnx2x 0000:04:00.0: 32.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x8 link)
[  319.680740] bnx2x 0000:04:00.1: msix capability found
[  319.685428] bnx2x 0000:04:00.0 eno49: renamed from eth0
[  319.698778] bnx2x 0000:04:00.1: part number 0-0-0-0
[  320.402118] bnx2x 0000:04:00.0 eno49: using MSI-X  IRQs: sp 67  fp[0] 69 ... fp[19] 118
[  321.171427] bnx2x 0000:04:00.1: 32.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x8 link)
[  321.173902] bnx2x 0000:04:00.1 eno50: renamed from eth0
[  321.811262] bnx2x 0000:04:00.1 eno50: using MSI-X  IRQs: sp 119  fp[0] 121 ... fp[19] 140
[  327.872503] bnx2x 0000:04:00.0 eno49: NIC Link is Up, 10000 Mbps full duplex, Flow control: none
[  329.525089] bnx2x 0000:04:00.1 eno50: NIC Link is Up, 10000 Mbps full duplex, Flow control: none

5. We can see that the network driver still loads correctly even after the patch is applied.

6. Running iperf3 -s on the server with my machine as the client we can see that the driver is also working as expected:

[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec   537 KBytes  4.40 Mbits/sec                  
[  5]   1.00-2.00   sec  1.35 MBytes  11.3 Mbits/sec                  
[  5]   2.00-3.00   sec  1.76 MBytes  14.8 Mbits/sec                  
[  5]   3.00-4.00   sec  1.75 MBytes  14.7 Mbits/sec                  
[  5]   4.00-5.00   sec  1.83 MBytes  15.4 Mbits/sec                  
[  5]   5.00-6.00   sec  1.79 MBytes  15.0 Mbits/sec                  
[  5]   6.00-7.00   sec  1.86 MBytes  15.6 Mbits/sec                  
[  5]   7.00-8.00   sec  2.27 MBytes  19.0 Mbits/sec                  
[  5]   8.00-9.00   sec  2.48 MBytes  20.8 Mbits/sec                  
[  5]   9.00-10.00  sec  2.60 MBytes  21.8 Mbits/sec                  
[  5]  10.00-10.18  sec   497 KBytes  22.3 Mbits/sec                  
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.18  sec  18.7 MBytes  15.4 Mbits/sec                  receiver