I am having the same issue using a Dock station Lenovo Thinkpad after the upgrade to the BigSur version.
panic(cpu 8 caller 0xffffff8004c9edf6): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff9361e6d000, prot:zero)
1672: 0xfffffffe00000000
Backtrace (CPU 8), Frame : Return Address
0xffffffb0cdc9acf0 : 0xffffff800448cfdd
0xffffffb0cdc9ad40 : 0xffffff80045d3fd3
0xffffffb0cdc9ad80 : 0xffffff80045c45ca
0xffffffb0cdc9add0 : 0xffffff8004431a2f
0xffffffb0cdc9adf0 : 0xffffff800448c7fd
0xffffffb0cdc9af10 : 0xffffff800448caf3
0xffffffb0cdc9af80 : 0xffffff8004c9cdca
0xffffffb0cdc9aff0 : 0xffffff8004c9edf6
0xffffffb0cdc9b470 : 0xffffff80044eb976
0xffffffb0cdc9b4e0 : 0xffffff800449c5ec
0xffffffb0cdc9b530 : 0xffffff8004bada32
0xffffffb0cdc9b550 : 0xffffff7f9e8fefe2
0xffffffb0cdc9b600 : 0xffffff7f9e8ff672
0xffffffb0cdc9b640 : 0xffffff7f9e8bfc62
0xffffffb0cdc9b660 : 0xffffff7f9f1f9e78
0xffffffb0cdc9b900 : 0xffffff7f9e8c0800
0xffffffb0cdc9b930 : 0xffffff7f9f1fb074
0xffffffb0cdc9b9c0 : 0xffffff7f9f1f90f7
0xffffffb0cdc9ba10 : 0xffffff7f9f1f8ee7
0xffffffb0cdc9ba60 : 0xffffff7f9f1f7f99
0xffffffb0cdc9baa0 : 0xffffff8004c1d67e
0xffffffb0cdc9baf0 : 0xffffff7f9e8c04be
0xffffffb0cdc9bb20 : 0xffffff8004c2792b
0xffffffb0cdc9bc80 : 0xffffff800457f7d1
0xffffffb0cdc9bd90 : 0xffffff800449265d
0xffffffb0cdc9be00 : 0xffffff8004468cd5
0xffffffb0cdc9be60 : 0xffffff80044801e2
0xffffffb0cdc9bef0 : 0xffffff80045a869d
0xffffffb0cdc9bfa0 : 0xffffff8004432216
Kernel Extensions in backtrace:
Topic:
App & System Services
SubTopic:
Core OS
Tags: