In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Associate BOs with every job that accesses them A submission can expand into a chain of jobs (e.g

Overview

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

drm/v3d: Associate BOs with every job that accesses them

A submission can expand into a chain of jobs (e.g. bin + render + cache clean). Implicit synchronization in v3d_submit_lock_reservations() is gated on each job's bo[], but the BO list was only ever attached to the last job of the chain. When that last job is a trailing CACHE_CLEAN job, the job that actually consumes the BOs (that is, a RENDER or CSD job) was left with bo_count == 0 and picked up no implicit dependencies. It could therefore be dispatched to the hardware and read a BO while another context was still writing it, leading to data corruption.

Attach the BOs to the job that consumes them, so (1) it acquires the correct implicit dependencies during reservation locking and (2) they are kept mapped until the end of the submission. Give it references to all consuming job's BOs through v3d_job_reference_bos() instead of looking the handles up a second time; that avoids a redundant lookup and guarantees both jobs reference the exact same objects.

As the CACHE_CLEAN job now carries a BO array as well, add a per-job has_implicit_dep flag so that only the consuming jobs take implicit dependencies. The CACHE_CLEAN job (a global flush) and the BIN job (binning waiting on another context is not a realistic scenario) are excluded.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.