CVE-2026-31533

CRITICAL EPSS 17.6%
Published Apr 23, 20262mo ago · Modified Jun 17, 20262w ago
9.8 CVSS 3.1
Critical
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Published Apr 23, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: net/tls: fix use-after-free in -EBUSY error path of tls_do_encryption The -EBUSY handling in tls_do_encryption(), introduced by commit 859054147318 ("net: tls: handle backlogging of crypto requests"), has a use-after-free due to double cleanup of encrypt_pending and the scatterlist entry. When crypto_aead_encrypt() returns -EBUSY, the request is enqueued to the cryptd backlog and the async callback tls_encrypt_done() will be invoked upon completion. That callback unconditionally restores the scatterlist entry (sge->offset, sge->length) and decrements ctx->encrypt_pending. However, if tls_encrypt_async_wait() returns an error, the synchronous error path in tls_do_encryption() performs the same cleanup again, double-decrementing encrypt_pending and double-restoring the scatterlist. The double-decrement corrupts the encrypt_pending sentinel (initialized to 1), making tls_encrypt_async_wait() permanently skip the wait for pending async callbacks. A subsequent sendmsg can then free the tls_rec via bpf_exec_tx_verdict() while a cryptd callback is still pending, resulting in a use-after-free when the callback fires on the freed record. Fix this by skipping the synchronous cleanup when the -EBUSY async wait returns an error, since the callback has already handled encrypt_pending and sge restoration.

CVSS Details

Base Score
9.8
Exploitability
3.9
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
17.6% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 14

VendorProductVersionRange
linuxlinux_kernel*≥5.15.160  –  <5.15.203
linuxlinux_kernel*≥6.1.84  –  <6.1.169
linuxlinux_kernel*≥6.6.18  –  <6.6.135
linuxlinux_kernel*≥6.7.6  –  <6.8
linuxlinux_kernel*≥6.8.1  –  <6.12.82
linuxlinux_kernel*≥6.13  –  <6.18.23
linuxlinux_kernel*≥6.19  –  <6.19.13
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any

References 7

  • git.kernel.org https://git.kernel.org/stable/c/02f3ecadb23558bbe068e6504118f1b712d4ece0
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/0e43e0a3c94044acc74b8e0927c27972eb5a59e8
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/2694d408b0e595024e0fc1d64ff9db0358580f74
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/414fc5e5a5aff776c150f1b86770e0a25a35df3a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5d70eb25b41e9b010828cd12818b06a0c3b04412
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a9b8b18364fffce4c451e6f6fd218fa4ab646705
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/aa9facde6c5005205874c37db3fd25799d741baf
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/02f3ecadb23558bbe068e6504118f1b712d4ece0
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/0e43e0a3c94044acc74b8e0927c27972eb5a59e8
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/2694d408b0e595024e0fc1d64ff9db0358580f74
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/414fc5e5a5aff776c150f1b86770e0a25a35df3a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5d70eb25b41e9b010828cd12818b06a0c3b04412
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a9b8b18364fffce4c451e6f6fd218fa4ab646705
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/aa9facde6c5005205874c37db3fd25799d741baf
    Patch