CVE-2026-31694

In the Linux kernel, the following vulnerability has been resolved:

fuse: reject oversized dirents in page cache

fuse_add_dirent_to_cache() computes a serialized dirent size from the

server-controlled namelen field and copies the dirent into a single

page-cache page. The existing logic only checks whether the dirent fits

in the remaining space of the current page and advances to a fresh page

if not. It never checks whether the dirent itself exceeds PAGE_SIZE.

As a result, a malicious FUSE server can return a dirent with

namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB

page systems this causes memcpy() to overflow the cache page by 24 bytes

into the following kernel page.

Reject dirents that cannot fit in a single page before copying them into

the readdir cache.