CVE-2026-98032tracing: Fix subbuf resize races with trace_pipe_raw readers

Official description

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix subbuf resize races with trace_pipe_raw readers Concurrent subbuffer resizes may crash trace_pipe_raw readers or leak uninitialized memory to userspace due to stale size values. Modify ring_buffer_alloc_read_page() to handle the resizing of an existing buffer_data_read_page if necessary and add a new ring_buffer_read_page_size(). This new function enables ring-buffer buffer_data_read_page users to not call the racy ring_buffer_subbuf_size_get(). This makes the spare_size member of ftrace_buffer_info redundant. Finally, handle buffer_data_read_page/reader_page order discrepancy in ring_buffer_read_page(). On a mismatch simply copy manually the data to the buffer_data_read_page.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/574efd988d116bd56ac688ab2d64e06ba0da982a
• https://git.kernel.org/stable/c/3f30b2cd4eba45c05f822f03f1b0f4077d6d4dc3
• https://git.kernel.org/stable/c/75b37b8369778b69ce9738d1c97685a1615cb252
• https://git.kernel.org/stable/c/dae8dda341d2d9034a90d59e8a7d502e1263813f