CVE-2023-52636

In the Linux kernel, the following vulnerability has been resolved:
libceph: just wait for more data to be available on the socket A short read
may occur while reading the message footer from the socket. Later, when the
socket is ready for another read, the messenger invokes all
read_partial_*() handlers, including read_partial_sparse_msg_data(). The
expectation is that read_partial_sparse_msg_data() would bail, allowing the
messenger to invoke read_partial() for the footer and pick up where it left
off. However read_partial_sparse_msg_data() violates that and ends up
calling into the state machine in the OSD client. The sparse-read state
machine assumes that it’s a new op and interprets some piece of the footer
as the sparse-read header and returns bogus extents/data length, etc. To
determine whether read_partial_sparse_msg_data() should bail, let’s reuse
cursor->total_resid. Because once it reaches to zero that means all the
extents and data have been successfully received in last read, else it
could break out when partially reading any of the extents and data. And
then osd_sparse_read() could continue where it left off. [ idryomov:
changelog ]