CVE-2022-49698 Information

Description

In the Linux kernel the following vulnerability has been resolved:

netfilter: use get_random_u32 instead of prandom

bh might occur while updating per-cpu rnd_state from user context ie. local_out path.

BUG: using smp_processor_id() in preemptible [00000000] code: nginx/2725 caller is nft_ng_random_eval+0x24/0x54 [nft_numgen] Call Trace: check_preemption_disabled+0xde/0xe0 nft_ng_random_eval+0x24/0x54 [nft_numgen]

Use the random driver instead this also avoids need for local prandom state. Moreover prandom now uses the random driver since d4150779e60f ( andom32: use real rng for non-deterministic randomness).

Based on earlier patch from Pablo Neira.

Reference

https://git.kernel.org/stable/c/15cc30ac2a8d7185f8ebf97dd1ddd90a7c79783b https://git.kernel.org/stable/c/6ce71f83f798be7e1ca68707fec449fbecb38852 https://git.kernel.org/stable/c/b1fd94e704571f98b21027340eecf821b2bdffba https://git.kernel.org/stable/c/d0906b0fffc9f19bc42708ca3e84e2089088386c