| Description: | In the Linux kernel before 5.4.2, the io_uring feature leads to requests that inadvertently have UID 0 and full capabilities, aka CID-181e448d8709. This is related to fs/io-wq.c, fs/io_uring.c, and net/socket.c. For example, an attacker can bypass intended restrictions on adding an IPv4 address to the loopback interface. This occurs because IORING_OP_SENDMSG operations, although requested in the context of an unprivileged user, are sometimes performed by a kernel worker thread without considering that context. It was discovered that the IO uring implementation in the Linux kernel did not properly perform credentials checks in certain situations. A local attacker could possibly use this to gain administrative privileges.
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