CVE-2022-48939

In the Linux kernel, the following vulnerability has been resolved:

bpf: Add schedule points in batch ops

syzbot reported various soft lockups caused by bpf batch operations.

INFO: task kworker/1:1:27 blocked for more than 140 seconds. INFO: task hung in rcu_barrier

Nothing prevents batch ops to process huge amount of data, we need to add schedule points in them.

Note that maybe_wait_bpf_programs(map) calls from generic_map_delete_batch() can be factorized by moving the call after the loop.

This will be done later in -next tree once we get this fix merged, unless there is strong opinion doing this optimization sooner.

Weakness

The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed.

Affected Software

References

• https://git.kernel.org/stable/c/75134f16e7dd0007aa474b281935c5f42e79f2c8
• https://git.kernel.org/stable/c/7e8099967d0e3ff9d1ae043e80b27fbe46c08417
• https://git.kernel.org/stable/c/7ef94bfb08fb9e73defafbd5ddef6b5a0e2ee12b
• https://git.kernel.org/stable/c/8628f489b749a4f9767991631921dbe3fbcdc784