CVE-2026-64062

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.