CVE-2020-12659

Se detectó un problema en el kernel de Linux versiones anteriores a 5.6.7. En la función xdp_umem_reg en el archivo net/xdp/xdp_umem.c se presenta una escritura fuera de límites (por un usuario con la capacidad CAP_NET_ADMIN) debido a una falta de comprobación del headroom.

An out-of-bounds (OOB) memory access flaw was found in the Network XDP (the eXpress Data Path) module in the Linux kernel's xdp_umem_reg function in net/xdp/xdp_umem.c. When a user with special user privilege of CAP_NET_ADMIN (or root) calls setsockopt to register umem ring on XDP socket, passing the headroom value larger than the available space in the chunk, it leads to an out-of-bounds write, causing panic or possible memory corruption. This flaw may lead to privilege escalation if a local end-user is granted permission to influence the execution of code in this manner.

It was discovered that the F2FS file system implementation in the Linux kernel did not properly perform bounds checking on xattrs in some situations. A local attacker could possibly use this to expose sensitive information. It was discovered that memory contents previously stored in microarchitectural special registers after RDRAND, RDSEED, and SGX EGETKEY read operations on Intel client and Xeon E3 processors may be briefly exposed to processes on the same or different processor cores. A local attacker could use this to expose sensitive information. Various other issues were also addressed.