CVE-2024-26800

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: tls: corrige el use-after-free en el descifrado fallido del trabajo pendiente Cuando la solicitud de descifrado va al trabajo pendiente y crypto_aead_decrypt devuelve -EBUSY, tls_do_decryption esperará hasta que se hayan completado todos los descifrados asíncronos. Si uno de ellos falla, tls_do_decryption devolverá -EBADMSG y tls_decrypt_sg salta a la ruta del error, liberando todas las páginas. Pero las páginas se pasaron a la devolución de llamada asíncrona y tls_decrypt_done ya las publicó. El único caso asíncrono verdadero es cuando crypto_aead_decrypt devuelve -EINPROGRESS. Con -EBUSY, ya esperamos para poder decirle a tls_sw_recvmsg que los datos están disponibles para copia inmediata, pero debemos notificar a tls_decrypt_sg (a través del nuevo indicador ->async_done) que la memoria ya ha sido liberada.

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.

Supraja Sridhara, Benedict Schlüter, Mark Kuhne, Andrin Bertschi, and Shweta Shinde discovered that the Confidential Computing framework in the Linux kernel for x86 platforms did not properly handle 32-bit emulation on TDX and SEV. An attacker with access to the VMM could use this to cause a denial of service or possibly execute arbitrary code. Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system.