CVE-2026-99036
dm: fix reading free memory in do_resume
Description
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.
INFO
Published Date :
Oct. 23, 2026, 1:17 p.m.
Last Modified :
Oct. 23, 2026, 1:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the Linux kernel commit that fixes the dm_table_get_mode race.
- Read the table mode before calling dm_swap_table.
- Ensure proper locking around table operations.
- Update the Linux kernel to the patched version.
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associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-99036
weaknesses.
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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
Oct. 23, 2026
Action Type Old Value New Value Added Description 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/99xxx/CVE-2026-99036.json">CVE-2026-99036</a> Added Reference https://git.kernel.org/stable/c/281f68d6cf8acb2547ebf0a849b8beae8fb0ec3c Added Reference https://git.kernel.org/stable/c/2c96d1a8324e7736e0f8a5790ecf39d36c2c4a82 Added Reference https://git.kernel.org/stable/c/301691c32b8ad023e3316d5dbb6a8cf52d47b0dc Added Reference https://git.kernel.org/stable/c/c9417c1c5269e2bd0570fbe53e4ec03a8d31f008 Added Reference https://git.kernel.org/stable/c/e3bf232c913b7e0103d323f15e6342d37cb1b357