Bug 2347983 (CVE-2022-49698)

Summary: CVE-2022-49698 kernel: netfilter: use get_random_u32 instead of prandom
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-26 03:13:33 UTC
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
("random32: use real rng for non-deterministic randomness").

Based on earlier patch from Pablo Neira.

Comment 1 Avinash Hanwate 2025-02-26 21:18:53 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022628-CVE-2022-49698-9ddd@gregkh/T