In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential deadlock in write-through mode Fix netfs_advance_writethrough() to always unlock the supplied folio and to mark it dirty if it isn't yet written to the end. Unfortunately, it can't be marked for writeback until the folio is done with as that may cause a deadlock against mmapped reads and writes. Even though it has been marked dirty, premature writeback can't occur as the caller is holding both inode->i_rwsem (which will prevent concurrent truncation, fallocation, DIO and other writes) and ictx->wb_lock (which will cause flushing to wait and writeback to skip or wait). Note that this may be easier to deal with once the queuing of folios is split from the generation of subrequests.
https://git.kernel.org/stable/c/e40e9cbf3ee4d30ee9a97bd128c85500b6ad0da1
https://git.kernel.org/stable/c/b6a4ae1634b3ad2aaa05222e53d36da532852faf
https://git.kernel.org/stable/c/1468f39243ccb155b6d97f9a9932f610d1205d75
https://git.kernel.org/stable/c/003aa0dd26c964025acd6d1213bcdbd674db2ca9