net/tls: fix use-after-free in -EBUSY error path of tls_do_encryption
Summary
| CVE | CVE-2026-31533 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-23 18:16:26 UTC |
| Updated | 2026-04-24 14:38:44 UTC |
| 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. |
Risk And Classification
EPSS: 0.000140000 probability, percentile 0.026590000 (date 2026-04-24)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 3ade391adc584f17b5570fd205de3ad029090368 414fc5e5a5aff776c150f1b86770e0a25a35df3a git | Not specified |
| CNA | Linux | Linux | affected cd1bbca03f3c1d845ce274c0d0a66de8e5929f72 02f3ecadb23558bbe068e6504118f1b712d4ece0 git | Not specified |
| CNA | Linux | Linux | affected 13eca403876bbea3716e82cdfe6f1e6febb38754 0e43e0a3c94044acc74b8e0927c27972eb5a59e8 git | Not specified |
| CNA | Linux | Linux | affected 8590541473188741055d27b955db0777569438e3 aa9facde6c5005205874c37db3fd25799d741baf git | Not specified |
| CNA | Linux | Linux | affected 8590541473188741055d27b955db0777569438e3 5d70eb25b41e9b010828cd12818b06a0c3b04412 git | Not specified |
| CNA | Linux | Linux | affected 8590541473188741055d27b955db0777569438e3 2694d408b0e595024e0fc1d64ff9db0358580f74 git | Not specified |
| CNA | Linux | Linux | affected 8590541473188741055d27b955db0777569438e3 a9b8b18364fffce4c451e6f6fd218fa4ab646705 git | Not specified |
| CNA | Linux | Linux | affected ab6397f072e5097f267abf5cb08a8004e6b17694 git | Not specified |
| CNA | Linux | Linux | affected 6.8 | Not specified |
| CNA | Linux | Linux | unaffected 6.8 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.203 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.169 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.135 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.82 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.23 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19.13 6.19.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/02f3ecadb23558bbe068e6504118f1b712d4ece0 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/414fc5e5a5aff776c150f1b86770e0a25a35df3a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5d70eb25b41e9b010828cd12818b06a0c3b04412 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/2694d408b0e595024e0fc1d64ff9db0358580f74 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0e43e0a3c94044acc74b8e0927c27972eb5a59e8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a9b8b18364fffce4c451e6f6fd218fa4ab646705 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/aa9facde6c5005205874c37db3fd25799d741baf | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.