Linux: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2025-22036 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 49b0a6ab8e528a0c1c50e37cef9b9c7c121365f2, f7447286363dc1e410bf30b87d75168f3519f9cc, f807a6bf2005740fa26b4f59c4a003dc966b9afd as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.2% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 49b0a6ab8e528a0c1c50e37cef9b9c7c121365f2 or f7447286363dc1e410bf30b87d75168f3519f9cc or f807a6bf2005740fa26b4f59c4a003dc966b9afd or 1bb7ff4204b6d4927e982cd256286c09ed4fd8ca, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.23 or 6.13.11 or 6.14.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 11a347fb6cef62ce47e84b97c45f2b2497c7593b up to, but not including, 49b0a6ab8e528a0c1c50e37cef9b9c7c121365f2; 11a347fb6cef62ce47e84b97c45f2b2497c7593b up to, but not including, f7447286363dc1e410bf30b87d75168f3519f9cc; 11a347fb6cef62ce47e84b97c45f2b2497c7593b up to, but not including, f807a6bf2005740fa26b4f59c4a003dc966b9afd; 11a347fb6cef62ce47e84b97c45f2b2497c7593b up to, but not including, 1bb7ff4204b6d4927e982cd256286c09ed4fd8ca; 6.8 | 49b0a6ab8e528a0c1c50e37cef9b9c7c121365f2, f7447286363dc1e410bf30b87d75168f3519f9cc, f807a6bf2005740fa26b4f59c4a003dc966b9afd, 1bb7ff4204b6d4927e982cd256286c09ed4fd8ca |
| Linux | Linux Kernel | 6.8 up to, but not including, 6.12.23; 6.13 up to, but not including, 6.13.11; 6.14 up to, but not including, 6.14.2 | 6.12.23, 6.13.11, 6.14.2 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.0 | High | NVD |
| CVSS 3.1 | 7.0 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: exfat: fix random stack corruption after get_block When get_block is called with a buffer_head allocated on the stack, such as do_mpage_readpage, stack corruption due to buffer_head UAF may occur in the following race condition situation. <CPU 0> <CPU 1> mpage_read_folio <<bh on stack>> do_mpage_readpage exfat_get_block bh_read __bh_read get_bh(bh) submit_bh wait_on_buffer ... end_buffer_read_sync __end_buffer_read_notouch unlock_buffer <<keep going>> ... ... ... ... <<bh is not valid out of mpage_read_folio>> . . another_function <<variable A on stack>> put_bh(bh) atomic_dec(bh->b_count) * stack corruption here * This patch returns -EAGAIN if a folio does not have buffers when bh_read needs to be called. By doing this, the caller can fallback to functions like block_read_full_folio(), create a buffer_head in the folio, and then call get_block again. Let's do not call bh_read() with on-stack buffer_head.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
How developers prevent this class of flaw
- In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
- Use thread-safe capabilities such as the data access abstraction in Spring.
- Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 7.0 High severity
- 7.0 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.1 High severity
- 7.0 High severity
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