CVE-2024-40935
Linux Kernel Cachefiles Request Hung Task Denial of Service
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.
INFO
Published Date :
July 12, 2024, 1:15 p.m.
Last Modified :
Nov. 21, 2024, 9:31 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
References to Advisories, Solutions, and Tools
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CVE-2024-40935.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2024-40935 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2024-40935
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2024-40935 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-40935 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/320ba9cbca78be79c912143bbba1d1b35ca55cf0 Added Reference https://git.kernel.org/stable/c/3bf0b8030296e9ee60d3d4c15849ad9ac0b47081 Added Reference https://git.kernel.org/stable/c/85e833cd7243bda7285492b0653c3abb1e2e757b Added Reference https://git.kernel.org/stable/c/e73fac95084839c5178d97e81c6a2051251bdc00 -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 12, 2024
Action Type Old Value New Value Added 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. Added Reference kernel.org https://git.kernel.org/stable/c/320ba9cbca78be79c912143bbba1d1b35ca55cf0 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/3bf0b8030296e9ee60d3d4c15849ad9ac0b47081 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/e73fac95084839c5178d97e81c6a2051251bdc00 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/85e833cd7243bda7285492b0653c3abb1e2e757b [No types assigned]