CVE-2024-27390: ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down()

Description

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

ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down()

As discussed in the past (commit 2d3916f31891 ("ipv6: fix skb drops
in igmp6_event_query() and igmp6_event_report()")) I think the
synchronize_net() call in ipv6_mc_down() is not needed.

Under load, synchronize_net() can last between 200 usec and 5 ms.

KASAN seems to agree as well.

Classification

CVE ID: CVE-2024-27390

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 12.41% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/9d159d6637ccce25f879d662a480541ef4ba3a50
https://git.kernel.org/stable/c/a03ede2282ebbd181bd6f5c38cbfcb5765afcd04
https://git.kernel.org/stable/c/26d4bac55750d535f1f0b8790dc26daf6089e373
https://git.kernel.org/stable/c/7eb06ee5921189812e6b4bfe7b0f1e878be16df7
https://git.kernel.org/stable/c/5da9a218340a2bc804dc4327e5804392e24a0b88
https://git.kernel.org/stable/c/17ef8efc00b34918b966388b2af0993811895a8c

Timeline