CVE-2026-98941

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

ext4: don't enable large folios on encrypted inodes

Commit 709f0f1f1bf5 ("ext4: add checks for large folio incompatibilities when BS > PS") disables large folios at mount time if the "encrypt" feature is set. However, enabling that feature on a mounted filesystem circumvents that check, and writing encrypted data results in a crash:

BUG: kernel NULL pointer dereference, address: 0000000000000028 Workqueue: ext4-rsv-conversion ext4 end io rsv work RIP: 0010:ext4 finish bio+0xf7/0x3e0 Call Trace: ext4 release io end+0x51/0x110 ext4 end io end+0x4c/0xe0 ext4 end io rsv work+0xb3/0x100

Fix this by disabling large folios on encrypted inodes, as is already done for inodes that use data journaling.

This affects all kernels between v6.19 and v7.2, but it is not needed in v7.3, where the code was significantly refactored.