CVE-2024-47678 Information

Nov 01, 2024 cve

Description

In the Linux kernel the following vulnerability has been resolved:

icmp: change the order of rate limits

ICMP messages are ratelimited :

After the blamed commits the two rate limiters are applied in this order:

  1. host wide ratelimit (icmp_global_allow())

  2. Per destination ratelimit (inetpeer based)

In order to avoid side-channels attacks we need to apply the per destination check first.

This patch makes the following change :

  1. icmp_global_allow() checks if the host wide limit is reached. But credits are not yet consumed. This is deferred to 3)

  2. The per destination limit is checked/updated. This might add a new node in inetpeer tree.

  3. icmp_global_consume() consumes tokens if prior operations succeeded.

This means that host wide ratelimit is still effective in keeping inetpeer tree small even under DDOS.

As a bonus I removed icmp_global.lock as the fast path can use a lock-free operation.

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Reference

https://git.kernel.org/stable/c/997ba8889611891f91e8ad83583466aeab6239a3 https://git.kernel.org/stable/c/662ec52260cc07b9ae53ecd3925183c29d34288b https://git.kernel.org/stable/c/a7722921adb046e3836eb84372241f32584bdb07 https://git.kernel.org/stable/c/483397b4ba280813e4a9c161a0a85172ddb43d19 https://git.kernel.org/stable/c/8c2bd38b95f75f3d2a08c93e35303e26d480d24e

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

NONE

Base Score

NONE

Base Severity

5.5

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