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

Read the record on cve.org

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

CVSSScoreVectorSource
3.19.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Affected Products

ProductVersions
LinuxLinux
  • f87e62d45e51b12d48d2cb46b5cde8f83b866bc4 to before a5de36d6cee74a92c1a21b260bc507e64bc451deAffected
  • f87e62d45e51b12d48d2cb46b5cde8f83b866bc4 to before 854cd32bc74fe573353095e90958490e4e4d641bAffected
  • f87e62d45e51b12d48d2cb46b5cde8f83b866bc4 to before 17153f154f80be2b47ebf52840f2d8f724eb2f3bAffected
  • f87e62d45e51b12d48d2cb46b5cde8f83b866bc4 to before 7bb09315f93dce6acc54bf59e5a95ba7365c2be4Affected
LinuxLinux
  • 5.3Affected
  • before 5.3Not affected
  • 6.12.75 through 6.12.*Not affected
  • 6.18.16 through 6.18.*Not affected
  • 6.19.6 through 6.19.*Not affected
  • 7.0 and laterNot affected

References

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