PT-2026-61475 · Linux · Linux
CVE-2026-64158
·
Published
2026-07-19
·
Updated
2026-07-19
CVSS v3.1
7.3
High
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L |
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix write streaming disablement if fd open O RDWR
In netfs perform write(), "write streaming" (the caching of dirty data in
dirty but !uptodate folios) is performed to avoid the need to read data
that is just going to get immediately overwritten. However, this is/will
be disabled in three circumstances: if the fd is open O RDWR, if fscache is
in use (as we need to round out the blocks for DIO) or if content
encryption is enabled (again for rounding out purposes).
The idea behind disabling it if the fd is open O RDWR is that we'd need to
flush the write-streaming page before we could read the data, particularly
through mmap. But netfs now fills in the gaps if ->read folio() is called
on the page, so that is unnecessary. Further, this doesn't actually work
if a separate fd is open for reading.
Fix this by removing the check for O RDWR, thereby allowing streaming
writes even when we might read.
This caused a number of problems with the generic/522 xfstest, but those
are now fixed.
Fix
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Related Identifiers
Affected Products
Linux