tracing: Fix WARN_ON in tracing_buffers_mmap_close

Summary

CVECVE-2026-23380
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-03-25 11:16:38 UTC
Updated2026-04-24 16:28:47 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: tracing: Fix WARN_ON in tracing_buffers_mmap_close When a process forks, the child process copies the parent's VMAs but the user_mapped reference count is not incremented. As a result, when both the parent and child processes exit, tracing_buffers_mmap_close() is called twice. On the second call, user_mapped is already 0, causing the function to return -ENODEV and triggering a WARN_ON. Normally, this isn't an issue as the memory is mapped with VM_DONTCOPY set. But this is only a hint, and the application can call madvise(MADVISE_DOFORK) which resets the VM_DONTCOPY flag. When the application does that, it can trigger this issue on fork. Fix it by incrementing the user_mapped reference count without re-mapping the pages in the VMA's open callback.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-617

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 91f3e8d84c89918769e71393f839c9fefadc2580 git Not specified
CNA Linux Linux affected cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 cdd96641b64297a2db42676f051362b76280a58b git Not specified
CNA Linux Linux affected cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0 git Not specified
CNA Linux Linux affected cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e git Not specified
CNA Linux Linux affected 6.10 Not specified
CNA Linux Linux unaffected 6.10 semver Not specified
CNA Linux Linux unaffected 6.12.77 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.17 6.18.* semver Not specified
CNA Linux Linux unaffected 6.19.7 6.19.* semver Not specified
CNA Linux Linux unaffected 7.0 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/91f3e8d84c89918769e71393f839c9fefadc2580 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/cdd96641b64297a2db42676f051362b76280a58b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
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