tcp: drop secpath at the same time as we currently drop dst
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.1.130, 6.6.80, 6.12.17, 6.13.5
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
In the Linux kernel, the following vulnerability has been resolved: tcp: drop secpath at the same time as we currently drop dst Xiumei reported hitting the WARN in xfrm6_tunnel_net_exit while running tests that boil down to: • create a pair of netns • run a basic TCP test over ipcomp6 • delete the pair of netns The xfrm_state found on spi_byaddr was not deleted at the time we delete the netns, because we still have a reference on it. This lingering reference comes from a secpath (which holds a ref on the xfrm_state), which is still attached to an skb. This skb is not leaked, it ends up on sk_receive_queue and then gets defer-free'd by skb_attempt_defer_free. The problem happens when we defer freeing an skb (push it on one CPU's defer_list), and don't flush that list before the netns is deleted. In that case, we still have a reference on the xfrm_state that we don't expect at this point. We already drop the skb's dst in the TCP receive path when it's no longer needed, so let's also drop the secpath. At this point, tcp_filter has already called into the LSM hooks that may require the secpath, so it should not be needed anymore. However, in some of those places, the MPTCP extension has just been attached to the skb, so we cannot simply drop all extensions.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Linux Linux
From 68822bdf76f10c3dc80609d4e2cdc1e847429086 · fixed in 87858bbf21da239ace300d61dd209907995c0491; From 68822bdf76f10c3dc80609d4e2cdc1e847429086 · fixed in f1d5e6a5e468308af7759cf5276779d3155c5e98; From 68822bdf76f10c3dc80609d4e2cdc1e847429086 · fixed in cd34a07f744451e2ecf9005bb7d24d0b2fb83656; From 68822bdf76f10c3dc80609d4e2cdc1e847429086 · fixed in 69cafd9413084cd5012cf5d7c7ec6f3d493726d9; From 68822bdf76f10c3dc80609d4e2cdc1e847429086 · fixed in 9b6412e6979f6f9e0632075f8f008937b5cd4efd
- Linux Linux
5.19
- KernelLinux
From 5.19.0 · fixed in 6.1.130; From 6.2.0 · fixed in 6.6.80; From 6.7.0 · fixed in 6.12.17; From 6.13.0 · fixed in 6.13.5