Red Hat: CVE-2024-44947: kernel: fuse: Initialize beyond-EOF page contents before setting uptodate (Multiple Advisories)

Red Hat: CVE-2024-44947: kernel: fuse: Initialize beyond-EOF page contents before setting uptodate (Multiple Advisories)

Severity

5

CVSS

(AV:L/AC:L/Au:S/C:C/I:N/A:N)

Published

09/02/2024

Created

12/06/2024

Added

12/05/2024

Modified

12/05/2024

Description

In the Linux kernel, the following vulnerability has been resolved: fuse: Initialize beyond-EOF page contents before setting uptodate fuse_notify_store(), unlike fuse_do_readpage(), does not enable page zeroing (because it can be used to change partial page contents). So fuse_notify_store() must be more careful to fully initialize page contents (including parts of the page that are beyond end-of-file) before marking the page uptodate. The current code can leave beyond-EOF page contents uninitialized, which makes these uninitialized page contents visible to userspace via mmap(). This is an information leak, but only affects systems which do not enable init-on-alloc (via CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y or the corresponding kernel command line parameter).

Solution(s)

• redhat-upgrade-kernel
• redhat-upgrade-kernel-rt

References

• CVE-2024-44947
• RHSA-2024:9315