net: psp: do not inherit the Rx association on clone
Affects Linux kernel 6.18.0 to before 6.18.59 and 6.19.0 to before 7.2.13 when a socket with a PSP association is cloned or accepted from a listener. Fixed in 6.18.59 and 7.2.13.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 33/100
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 6.18.59, 7.2.13
- 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
Summary
The vulnerability affects the Linux kernel's PSP (Path Security Protocol) networking code, specifically how TCP sockets handle the PSP association when a listening socket accepts connections or is reconfigured. Improper reference handling can lead to a use-after-free condition, which may allow a local user to crash the system or potentially corrupt kernel memory.
Read the original description
In the Linux kernel, the following vulnerability has been resolved: net: psp: do not inherit the Rx association on clone sk->psp_assoc sits past sk_dontcopy_end, so sock_copy() copies it into every socket accepted from a listener without taking a reference, while inet_sock_destruct() puts for every inet socket. psp_twsk_init() does refcount_inc() for the timewait socket, so a child closing through TIME_WAIT cancels its own put and leaves the association with one reference and N timewait sockets holding the same pointer. Closing the listener frees it, and the timewait timers then put freed memory. Rejecting the association on a listening socket is not sufficient: a socket can acquire one while established and then be turned back into a listener, because tcp_disconnect() leaves sk->psp_assoc in place. BUG: KASAN: slab-use-after-free in psp_twsk_assoc_free+0x6f/0xf0 Write of size 4 at addr ffff888110f9255c by task swapper/7/0 psp_twsk_assoc_free+0x6f/0xf0 inet_twsk_put+0xda/0x1b0 call_timer_fn+0x53/0x2e0 __run_timers+0x764/0xa80 Freed by task 99: kfree+0x1a7/0x500 process_one_work+0x7ec/0x1100 An association carries a per-connection SPI and key, so a child must not inherit the parent's. Clear it on clone.
What to do
Check whether your setup matches what the bug needs.
The socket holds a PSP security association (sk->psp_assoc) when it is cloned or accepted from a listener. A socket that was established with a PSP association and then turned back into a listener via tcp_disconnect() keeps that association.Upgrade to a fixed version: 6.18.59, 7.2.13.
Timeline
- CVE published
- First seen by cve.now3 days
- Record last updated
- Posted on X by cve.now
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
6.18
- KernelLinux
From 6.18.0 · fixed in 6.18.59; From 6.19.0 · fixed in 7.2.13
Evidence 3
- Link
- Link
- Link
Corrections
None so far.
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Questions about CVE-2026-99116
What does this mean?
When a socket that holds a PSP security association is cloned or accepted from a listener, the copy keeps that association. A socket that had a PSP association and was later turned back into a listener with tcp_disconnect() also keeps it. After the listener is closed, TIME_WAIT timers can put memory that was already freed, which corrupts kernel memory.Source: git.kernel.org
Am I affected, and how do I check?
Affected kernels are 6.18.0 through 6.18.59 and 6.19.0 through 7.2.12. To check a system, run uname -r to see the running kernel version. The bug needs a socket that holds a PSP association and is cloned, accepted from a listener, or turned into a listener with tcp_disconnect().Source: git.kernel.org
What should I do about it?
Update to kernel 6.18.59 or 7.2.13, whichever matches the release line in use. These are the fixed versions listed for the affected ranges.Source: git.kernel.org
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data