CVE-2026-23240
tls: Fix race condition in tls_sw_cancel_work_tx()
- State
- Published
- Severity
- 9.8 Critical
- Published
- Mar 10, 2026
- Updated
- Oct 19, 2026
- Reserved
- Jan 13, 2026
Description
In the Linux kernel, the following vulnerability has been resolved:
tls: Fix race condition in tls_sw_cancel_work_tx()
This issue was discovered during a code audit.
After cancel_delayed_work_sync() is called from tls_sk_proto_close(), tx_work_handler() can still be scheduled from paths such as the Delayed ACK handler or ksoftirqd. As a result, the tx_work_handler() worker may dereference a freed TLS object.
The following is a simple race scenario:
cpu0 cpu1
tls_sk_proto_close() tls_sw_cancel_work_tx() tls_write_space() tls_sw_write_space() if (!test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx->tx_bitmask)) set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask); cancel_delayed_work_sync(&ctx->tx_work.work); schedule_delayed_work(&tx_ctx->tx_work.work, 0);
To prevent this race condition, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync().
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | Linux |
Weaknesses
- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Products
| Product | Versions |
|---|---|
LinuxLinux |
|
LinuxLinux |
|
References
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