vulnerability
Amazon Linux 2023: CVE-2024-40935: Important priority package update for kernel
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:L/AC:L/Au:S/C:N/I:N/A:C) | Jul 12, 2024 | Mar 27, 2025 | Oct 16, 2025 |
Severity
5
CVSS
(AV:L/AC:L/Au:S/C:N/I:N/A:C)
Published
Jul 12, 2024
Added
Mar 27, 2025
Modified
Oct 16, 2025
Description
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: flush all requests after setting CACHEFILES_DEAD
In ondemand mode, when the daemon is processing an open request, if the
kernel flags the cache as CACHEFILES_DEAD, the cachefiles_daemon_write()
will always return -EIO, so the daemon can't pass the copen to the kernel.
Then the kernel process that is waiting for the copen triggers a hung_task.
Since the DEAD state is irreversible, it can only be exited by closing
/dev/cachefiles. Therefore, after calling cachefiles_io_error() to mark
the cache as CACHEFILES_DEAD, if in ondemand mode, flush all requests to
avoid the above hungtask. We may still be able to read some of the cached
data before closing the fd of /dev/cachefiles.
Note that this relies on the patch that adds reference counting to the req,
otherwise it may UAF.
cachefiles: flush all requests after setting CACHEFILES_DEAD
In ondemand mode, when the daemon is processing an open request, if the
kernel flags the cache as CACHEFILES_DEAD, the cachefiles_daemon_write()
will always return -EIO, so the daemon can't pass the copen to the kernel.
Then the kernel process that is waiting for the copen triggers a hung_task.
Since the DEAD state is irreversible, it can only be exited by closing
/dev/cachefiles. Therefore, after calling cachefiles_io_error() to mark
the cache as CACHEFILES_DEAD, if in ondemand mode, flush all requests to
avoid the above hungtask. We may still be able to read some of the cached
data before closing the fd of /dev/cachefiles.
Note that this relies on the patch that adds reference counting to the req,
otherwise it may UAF.
Solutions
amazon-linux-2023-upgrade-bpftoolamazon-linux-2023-upgrade-bpftool-debuginfoamazon-linux-2023-upgrade-kernelamazon-linux-2023-upgrade-kernel-debuginfoamazon-linux-2023-upgrade-kernel-debuginfo-common-aarch64amazon-linux-2023-upgrade-kernel-debuginfo-common-x86-64amazon-linux-2023-upgrade-kernel-develamazon-linux-2023-upgrade-kernel-headersamazon-linux-2023-upgrade-kernel-libbpfamazon-linux-2023-upgrade-kernel-libbpf-develamazon-linux-2023-upgrade-kernel-libbpf-staticamazon-linux-2023-upgrade-kernel-livepatch-6-1-96-102-177amazon-linux-2023-upgrade-kernel-modules-extraamazon-linux-2023-upgrade-kernel-modules-extra-commonamazon-linux-2023-upgrade-kernel-toolsamazon-linux-2023-upgrade-kernel-tools-debuginfoamazon-linux-2023-upgrade-kernel-tools-develamazon-linux-2023-upgrade-perfamazon-linux-2023-upgrade-perf-debuginfoamazon-linux-2023-upgrade-python3-perfamazon-linux-2023-upgrade-python3-perf-debuginfo
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