CVE-2026-74647

In the Linux kernel, the following vulnerability has been resolved:

misc: fastrpc: Remove buffer from list prior to unmap operation

fastrpc_req_munmap_impl() is called to unmap any buffer. The buffer is

getting removed from the list after it is unmapped from DSP. This can

create potential race conditions if multiple threads invoke unmap

concurrently, where one thread may remove the entry from the list while

another thread's unmap operation is still ongoing.

Fix this by removing the buffer entry from the list before calling the

unmap operation. If the unmap fails, the entry is re-added to the list

so that userspace can retry the unmap, or alternatively, the buffer

will be cleaned up during device release when the DSP process is torn

down and all DSP-side mappings are freed along with remaining buffers

in the list.