CVE-2021-47012

In the Linux kernel, the following vulnerability has been resolved:
RDMA/siw: Fix a use after free in siw_alloc_mr Our code analyzer reported a
UAF. In siw_alloc_mr(), it calls siw_mr_add_mem(mr,…). In the
implementation of siw_mr_add_mem(), mem is assigned to mr->mem and then mem
is freed via kfree(mem) if xa_alloc_cyclic() failed. Here, mr->mem still
point to a freed object. After, the execution continue up to the err_out
branch of siw_alloc_mr, and the freed mr->mem is used in
siw_mr_drop_mem(mr). My patch moves “mr->mem = mem” behind the if
(xa_alloc_cyclic(…)<0) {} section, to avoid the uaf.