Race condition reads freed memory in Linux kernel device mapper
Key facts
- Attack vector
- —
- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
- —
- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 7 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel device mapper function do_resume calls dm_table_get_mode without holding a lock, so a concurrent ioctl can swap the table first and make the code read freed memory. Only root can trigger it, and the CNA states that it is not a security bug because common tools do not issue the ioctls concurrently.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: dm: fix reading free memory in do_resume When do_resume calls dm_table_get_mode(new_map), the call is done without holding any locks (it only holds a reference to the md). It may be possible that another concurrent ioctl on the same device will swap table after dm_swap_table and before dm_table_get_mode. In this case, dm_table_get_mode(new_map) reads freed memory. This race condition was triggered by syzbot. This commit fixes the race by reading mode of the new table before dm_swap_table. Note that new_map is also passed to dm_ima_need_measure, but this function doesn't attempt to dereference it, so this call should be safe. Note that this is not a security bug because only root can trigger it and the commonly used tools such as lvm or cryptsetup do not call the ioctls concurrently, so that they can't trigger it acceidentally.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.29 and later | 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11, 7.3 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.29 and later Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11, 7.3 Patch available CNA
Remediation
Update the Linux kernel to 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11 or 7.3. Red Hat Enterprise Linux 6 has no fix planned, and Red Hat Enterprise Linux 7, 8, 9 and 10 and OpenShift Container Platform 4 and 5 have no fix available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-23 Threatist record created from CVE-2026-99036
- 2026-10-23 Alias added: GHSA-4cj3-mpcr-rfqf
- 2026-10-26 Fix available: Linux/Linux@0 · CNA
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-29 CVSS score added · Red Hat
- 2026-10-30 Fix available: Linux/Linux@2bc5df0cf906f36a8f59ac864139ee2b7b53d3c0, Linux/Linux@48169328021dfd59121f9a66cca919b7defcd3fa, Linux/[email protected] +3 · CNA
- 2026-10-30 3 new references · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/2bc5df0cf906f36a8f59ac864139ee2b7b53d3c0
- https://git.kernel.org/stable/c/48169328021dfd59121f9a66cca919b7defcd3fa
- https://git.kernel.org/stable/c/7a272c2338f758e3b6e664ebf7488ac40f48a2a4
- https://git.kernel.org/stable/c/281f68d6cf8acb2547ebf0a849b8beae8fb0ec3c
- https://git.kernel.org/stable/c/2c96d1a8324e7736e0f8a5790ecf39d36c2c4a82
- https://git.kernel.org/stable/c/e3bf232c913b7e0103d323f15e6342d37cb1b357
- https://git.kernel.org/stable/c/301691c32b8ad023e3316d5dbb6a8cf52d47b0dc
- https://git.kernel.org/stable/c/c9417c1c5269e2bd0570fbe53e4ec03a8d31f008
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Sources
- CVE-2026-99036 · CVE Program
- CVE-2026-99036 · NVD
- FIRST EPSS
- GHSA-4cj3-mpcr-rfqf · GitHub Advisory Database · CC BY 4.0
- CVE-2026-99036 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences