CVE-2025-68356
gfs2: Prevent recursive memory reclaim
Description
In the Linux kernel, the following vulnerability has been resolved: gfs2: Prevent recursive memory reclaim Function new_inode() returns a new inode with inode->i_mapping->gfp_mask set to GFP_HIGHUSER_MOVABLE. This value includes the __GFP_FS flag, so allocations in that address space can recurse into filesystem memory reclaim. We don't want that to happen because it can consume a significant amount of stack memory. Worse than that is that it can also deadlock: for example, in several places, gfs2_unstuff_dinode() is called inside filesystem transactions. This calls filemap_grab_folio(), which can allocate a new folio, which can trigger memory reclaim. If memory reclaim recurses into the filesystem and starts another transaction, a deadlock will ensue. To fix these kinds of problems, prevent memory reclaim from recursing into filesystem code by making sure that the gfp_mask of inode address spaces doesn't include __GFP_FS. The "meta" and resource group address spaces were already using GFP_NOFS as their gfp_mask (which doesn't include __GFP_FS). The default value of GFP_HIGHUSER_MOVABLE is less restrictive than GFP_NOFS, though. To avoid being overly limiting, use the default value and only knock off the __GFP_FS flag. I'm not sure if this will actually make a difference, but it also shouldn't hurt. This patch is loosely based on commit ad22c7a043c2 ("xfs: prevent stack overflows from page cache allocation"). Fixes xfstest generic/273.
INFO
Published Date :
Dec. 24, 2025, 11:15 a.m.
Last Modified :
Dec. 24, 2025, 11:15 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2025-68356
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Modify gfp_mask to exclude __GFP_FS flag.
- Ensure address spaces do not include __GFP_FS.
- Update Linux kernel to apply the fix.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-68356.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-68356 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-2025-68356
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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The following list is the news that have been mention
CVE-2025-68356 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-68356 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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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Dec. 24, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: gfs2: Prevent recursive memory reclaim Function new_inode() returns a new inode with inode->i_mapping->gfp_mask set to GFP_HIGHUSER_MOVABLE. This value includes the __GFP_FS flag, so allocations in that address space can recurse into filesystem memory reclaim. We don't want that to happen because it can consume a significant amount of stack memory. Worse than that is that it can also deadlock: for example, in several places, gfs2_unstuff_dinode() is called inside filesystem transactions. This calls filemap_grab_folio(), which can allocate a new folio, which can trigger memory reclaim. If memory reclaim recurses into the filesystem and starts another transaction, a deadlock will ensue. To fix these kinds of problems, prevent memory reclaim from recursing into filesystem code by making sure that the gfp_mask of inode address spaces doesn't include __GFP_FS. The "meta" and resource group address spaces were already using GFP_NOFS as their gfp_mask (which doesn't include __GFP_FS). The default value of GFP_HIGHUSER_MOVABLE is less restrictive than GFP_NOFS, though. To avoid being overly limiting, use the default value and only knock off the __GFP_FS flag. I'm not sure if this will actually make a difference, but it also shouldn't hurt. This patch is loosely based on commit ad22c7a043c2 ("xfs: prevent stack overflows from page cache allocation"). Fixes xfstest generic/273. Added Reference https://git.kernel.org/stable/c/2c5f4a53476e3cab70adc77b38942c066bd2c17c Added Reference https://git.kernel.org/stable/c/49e7347f4644d031306d56cb4d51e467cbdcbc69 Added Reference https://git.kernel.org/stable/c/9c0960ed112398bdb6c60ccf6e6b583bc59acede Added Reference https://git.kernel.org/stable/c/edb2b255618621dc83d0ec23150e16b2c697077f