CVE-2025-38616 tls: handle data disappearing from under the TLS ULP
A use-after-free in the Linux kernel TLS module allows attackers to cause a crash or undefined behavior by racing with socket reads.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-38616?
CVE-2025-38616 is a high-severity use after free vulnerability in Linux kernel, published on 22 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
tls: handle data disappearing from under the TLS ULP
TLS expects that it owns the receive queue of the TCP socket. This cannot be guaranteed in case the reader of the TCP socket entered before the TLS ULP was installed, or uses some non-standard read API (eg. zerocopy ones). Replace the WARN_ON() and a buggy early exit (which leaves anchor pointing to a freed skb) with real error handling. Wipe the parsing state and tell the reader to retry.
We already reload the anchor every time we (re)acquire the socket lock, so the only condition we need to avoid is an out of bounds read (not having enough bytes in the socket for previously parsed record len).
If some data was read from under TLS but there's enough in the queue we'll reload and decrypt what is most likely not a valid TLS record. Leading to some undefined behavior from TLS perspective (corrupting a stream? missing an alert? missing an attack?) but no kernel crash should take place.
Weakness: CWE-125
Which versions are affected by CVE-2025-38616?
It affects 1 product.
Linux distribution packages (9)
kernel-livepatch-SLE15-SP6_Update_15 SUSE:Linux Enterprise Live Patching 15 SP6 | All versions | 4-150600.2.1 |
kernel-livepatch-SLE15-SP7-RT_Update_4 SUSE:Linux Enterprise Live Patching 15 SP7 | All versions | 4-150700.2.1 |
kernel-livepatch-SLE15-SP7_Update_4 SUSE:Linux Enterprise Live Patching 15 SP7 | All versions | 4-150700.2.1 |
kernel-livepatch-MICRO-6-0-RT_Update_12 SUSE:Linux Micro 6.0 | All versions | 3-1.1 |
kernel-livepatch-MICRO-6-0_Update_11 SUSE:Linux Micro 6.0 | All versions | 3-1.1 |
kernel-livepatch-MICRO-6-0_Update_12 SUSE:Linux Micro 6.0 | All versions | 3-1.1 |
kernel-livepatch-MICRO-6-0-RT_Update_12 SUSE:Linux Micro 6.1 | All versions | 3-1.1 |
kernel-livepatch-MICRO-6-0_Update_11 SUSE:Linux Micro 6.1 | All versions | 3-1.1 |
kernel-livepatch-MICRO-6-0_Update_12 SUSE:Linux Micro 6.1 | All versions | 3-1.1 |
Products include Linux kernel.
How do I fix CVE-2025-38616?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-38616 being exploited?
There is no known exploitation of CVE-2025-38616 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as A-440544812, ASB-A-440544812, AZL-66662, BELL-CVE-2025-38616, DEBIAN-CVE-2025-38616, GHSA-jwf8-43xw-qvcr and 13 more.