CVE-2024-26800
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk20th percentile - higher than 20% of all known CVEs
Summary
Use-after-free vulnerability in the Linux kernel's TLS implementation during failed backlog decryption. When the crypto operation returns -EBUSY, tls_do_decryption waits for all async decryptions to complete, and if one fails, pages are released but have already been passed to the async callback.
Risk Assessment
May lead to memory corruption, system crash, or potentially remote code execution in kernel context.
Recommendation
Apply the Linux kernel update that includes the fix for this issue.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: tls: fix use-after-free on failed backlog decryption When the decrypt request goes to the backlog and crypto_aead_decrypt returns -EBUSY, tls_do_decryption will wait until all async decryptions have completed. If one of them fails, tls_do_decryption will return -EBADMSG and tls_decrypt_sg jumps to the error path, releasing all the pages. But the pages have been passed to the async callback, and have already been released by tls_decrypt_done. The only true async case is when crypto_aead_decrypt returns -EINPROGRESS. With -EBUSY, we already waited so we can tell tls_sw_recvmsg that the data is available for immediate copy, but we need to notify tls_decrypt_sg (via the new ->async_done flag) that the memory has already been released.