Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
tls: Purge async_hold in tls_decrypt_async_wait()
The async_hold queue pins encrypted input skbs while the AEAD engine references their scatterlist data. Once tls_decrypt_async_wait() returns, every AEAD operation has completed and the engine no longer references those skbs, so they can be freed unconditionally.
A subsequent patch adds batch async decryption to tls_sw_read_sock(), introducing a new call site that must drain pending AEAD operations and release held skbs. Move __skb_queue_purge(&ctx->async_hold) into tls_decrypt_async_wait() so the purge is centralized and every caller – recvmsg’s drain path, the -EBUSY fallback in tls_do_decryption(), and the new read_sock batch path – releases held skbs on synchronization without each site managing the purge independently.
This fixes a leak when tls_strp_msg_hold() fails part-way through, after having added some cloned skbs to the async_hold queue. tls_decrypt_sg() will then call tls_decrypt_async_wait() to process all pending decrypts, and drop back to synchronous mode, but tls_sw_recvmsg() only flushes the async_hold queue when one record has been processed in “fully-async” mode, which may not be the case here.
[[email protected]: added leak comment]
Details
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Debian 12 | Released |
4 kernels
|
| Debian 13 | Planned | — |
| Ubuntu 24.04 | Planned | — |