CVE-2026-23380
Description
In 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.
CVSS Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Threat Intelligence
Weaknesses 1
Affected Products 11
| Vendor | Product | Version | Range |
|---|---|---|---|
| linux | linux_kernel | * | ≥6.10.1 – <6.12.77 |
| linux | linux_kernel | * | ≥6.13 – <6.18.17 |
| linux | linux_kernel | * | ≥6.19 – <6.19.7 |
| linux | linux_kernel | 6.10 | any |
| linux | linux_kernel | 7.0 | any |
| linux | linux_kernel | 7.0 | any |
| linux | linux_kernel | 7.0 | any |
| linux | linux_kernel | 7.0 | any |
| linux | linux_kernel | 7.0 | any |
| linux | linux_kernel | 7.0 | any |
| linux | linux_kernel | 7.0 | any |
References 4
- git.kernel.org https://git.kernel.org/stable/c/91f3e8d84c89918769e71393f839c9fefadc2580
- git.kernel.org https://git.kernel.org/stable/c/b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0
- git.kernel.org https://git.kernel.org/stable/c/cdd96641b64297a2db42676f051362b76280a58b
- git.kernel.org https://git.kernel.org/stable/c/e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e
Remediation
- git.kernel.org https://git.kernel.org/stable/c/91f3e8d84c89918769e71393f839c9fefadc2580
- git.kernel.org https://git.kernel.org/stable/c/b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0
- git.kernel.org https://git.kernel.org/stable/c/cdd96641b64297a2db42676f051362b76280a58b
- git.kernel.org https://git.kernel.org/stable/c/e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e