RDMA/bnxt_re: Avoid CPU lockups due fifo occupancy check loop

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/bnxt_re: Avoid CPU lockups due fifo occupancy check loop Driver waits indefinitely for the fifo occupancy to go below a threshold as soon as the pacing interrupt is received. This can cause soft lockup on one of the processors, if the rate of DB is very high. Add a loop count for FPGA and exit the __wait_for_fifo_occupancy_below_th if the loop is taking more time. Pacing will be continuing until the occupancy is below the threshold. This is ensured by the checks in bnxt_re_pacing_timer_exp and further scheduling the work for pacing based on the fifo occupancy.

References

• https://git.kernel.org/stable/c/7998e7efd1d557af118ac96f48ebc569b929b555
• https://git.kernel.org/stable/c/2fb6b2e82413e401b72dfeacd7a60416fcfc5b41
• https://git.kernel.org/stable/c/8be3e5b0c96beeefe9d5486b96575d104d3e7d17