gpu: host1x: Fix race in syncpt alloc/free

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: gpu: host1x: Fix race in syncpt alloc/free Fix race condition between host1x_syncpt_alloc() and host1x_syncpt_put() by using kref_put_mutex() instead of kref_put() + manual mutex locking. This ensures no thread can acquire the syncpt_mutex after the refcount drops to zero but before syncpt_release acquires it. This prevents races where syncpoints could be allocated while still being cleaned up from a previous release. Remove explicit mutex locking in syncpt_release as kref_put_mutex() handles this atomically.

References

• https://git.kernel.org/stable/c/ca9388fba50dac2eb71c13702b7022a801bef90e
• https://git.kernel.org/stable/c/4aeaece518fa4436af93d1d8b786200d9656ff4b
• https://git.kernel.org/stable/c/6245cce711e2cdb2cc75c0bb8632952e36f8c972
• https://git.kernel.org/stable/c/4e6e07ce0197aecfb6c4a62862acc93b3efedeb7
• https://git.kernel.org/stable/c/d138f73ffb0c57ded473c577719e6e551b7b1f27
• https://git.kernel.org/stable/c/79197c6007f2afbfd7bcf5b9b80ccabf8483d774
• https://git.kernel.org/stable/c/c7d393267c497502fa737607f435f05dfe6e3d9b