CVE-2026-23240

Summary

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().

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxf87e62d45e51b12d48d2cb46b5cde8f83b866bc4 < a5de36d6cee74a92c1a21b260bc507e64bc451deaffected
LinuxLinuxf87e62d45e51b12d48d2cb46b5cde8f83b866bc4 < 854cd32bc74fe573353095e90958490e4e4d641baffected
LinuxLinuxf87e62d45e51b12d48d2cb46b5cde8f83b866bc4 < 17153f154f80be2b47ebf52840f2d8f724eb2f3baffected
LinuxLinuxf87e62d45e51b12d48d2cb46b5cde8f83b866bc4 < 7bb09315f93dce6acc54bf59e5a95ba7365c2be4affected
LinuxLinux5.3affected
LinuxLinux0 < 5.3unaffected
LinuxLinux6.12.75 <= 6.12.*unaffected
LinuxLinux6.18.16 <= 6.18.*unaffected
LinuxLinux6.19.6 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References