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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 to < 91f3e8d84c89918769e71393f839c9fefadc2580affectedcf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 to < cdd96641b64297a2db42676f051362b76280a58baffectedcf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 to < b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0affectedcf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 to < e39bb9e02b68942f8e9359d2a3efe7d37ae6be0eaffected
Linux Linux
Default version status: affected
6.10affected0 to < 6.10unaffected6.12.77 to ≤ 6.12.*unaffected6.18.17 to ≤ 6.18.*unaffected6.19.7 to ≤ 6.19.*unaffected7.0 to ≤ *unaffected