CVE-2026-31533
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BaseFortify
Publication date: 2026-04-23
Last updated on: 2026-04-29
Assigner: kernel.org
Description
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 Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | From 6.7.6 (inc) to 6.8 (exc) |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | From 5.15.160 (inc) to 5.15.203 (exc) |
| linux | linux_kernel | From 6.1.84 (inc) to 6.1.169 (exc) |
| linux | linux_kernel | From 6.13 (inc) to 6.18.23 (exc) |
| linux | linux_kernel | From 6.19 (inc) to 6.19.13 (exc) |
| linux | linux_kernel | From 6.6.18 (inc) to 6.6.135 (exc) |
| linux | linux_kernel | From 6.8.1 (inc) to 6.12.82 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
Attack-Flow Graph
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