CVE-2026-23410
Received Received - Intake
Use-After-Free Race Condition in Linux AppArmor Rawdata Inodes

Publication date: 2026-04-01

Last updated on: 2026-04-24

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: apparmor: fix race on rawdata dereference There is a race condition that leads to a use-after-free situation: because the rawdata inodes are not refcounted, an attacker can start open()ing one of the rawdata files, and at the same time remove the last reference to this rawdata (by removing the corresponding profile, for example), which frees its struct aa_loaddata; as a result, when seq_rawdata_open() is reached, i_private is a dangling pointer and freed memory is accessed. The rawdata inodes weren't refcounted to avoid a circular refcount and were supposed to be held by the profile rawdata reference. However during profile removal there is a window where the vfs and profile destruction race, resulting in the use after free. Fix this by moving to a double refcount scheme. Where the profile refcount on rawdata is used to break the circular dependency. Allowing for freeing of the rawdata once all inode references to the rawdata are put.
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Meta Information
Published
2026-04-01
Last Modified
2026-04-24
Generated
2026-05-07
AI Q&A
2026-04-01
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 15 associated CPEs
Vendor Product Version / Range
linux linux_kernel 4.13
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel From 6.2 (inc) to 6.6.130 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.77 (exc)
linux linux_kernel From 5.11 (inc) to 5.15.203 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.169 (exc)
linux linux_kernel From 6.13 (inc) to 6.18.18 (exc)
linux linux_kernel From 6.19 (inc) to 6.19.8 (exc)
linux linux_kernel From 4.13.1 (inc) to 5.10.253 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-362 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.
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a race condition in the Linux kernel's AppArmor component related to rawdata inodes. Because these rawdata inodes are not reference counted, an attacker can open a rawdata file while simultaneously removing the last reference to that rawdata, such as by deleting the associated profile. This causes the underlying data structure (struct aa_loaddata) to be freed prematurely. When the system later tries to access this freed memory, it results in a use-after-free situation where a dangling pointer is dereferenced.

The root cause is that rawdata inodes were not refcounted to avoid circular references, relying instead on the profile's rawdata reference. However, during profile removal, a timing window exists where the virtual file system (vfs) and profile destruction race, leading to this unsafe memory access.

The fix involves implementing a double reference counting scheme to properly manage the lifecycle of rawdata, breaking the circular dependency and ensuring that rawdata is only freed once all inode references are released.


How can this vulnerability impact me? :

This vulnerability can lead to a use-after-free condition in the Linux kernel, which may allow an attacker to cause memory corruption or potentially execute arbitrary code with kernel privileges. Exploiting this race condition could compromise system stability, cause crashes, or enable privilege escalation.


What immediate steps should I take to mitigate this vulnerability?

The vulnerability is fixed by applying the patch that moves to a double refcount scheme in the Linux kernel AppArmor component. Immediate mitigation involves updating the Linux kernel to a version that includes this fix.

Since the issue involves a race condition in AppArmor's handling of rawdata inodes, ensuring your system is running the patched kernel version will prevent the use-after-free condition.


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