gpu: host1x: Allow entries in BO caches to be freed
When a buffer object is pinned via host1x_bo_pin() with a cache, the
resulting mapping is kept in the cache so it can be reused on subsequent
pins. Each mapping held a reference to the underlying host1x_bo (taken
in tegra_bo_pin / gather_bo_pin), so as long as a mapping was cached,
the bo itself could not be freed.
However, the only way to remove the cached mapping was through the free
path of the buffer object. This meant that if a bo got cached, it could
never get freed again.
Resolve the circularity by holding a weak reference to the bo from the
cache side. This is done by having the .pin callbacks not bump the bo's
refcount -- instead the common Host1x bo code does so, except for the
cache reference.
Also move the remove-cache-mapping-on-free code into a common function
inside Host1x code. This is only called from the TegraDRM GEM buffers
since those are the only ones that can be cached at the moment.
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Sat, 15 Aug 2026 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-409 |
Sat, 15 Aug 2026 06:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: gpu: host1x: Allow entries in BO caches to be freed When a buffer object is pinned via host1x_bo_pin() with a cache, the resulting mapping is kept in the cache so it can be reused on subsequent pins. Each mapping held a reference to the underlying host1x_bo (taken in tegra_bo_pin / gather_bo_pin), so as long as a mapping was cached, the bo itself could not be freed. However, the only way to remove the cached mapping was through the free path of the buffer object. This meant that if a bo got cached, it could never get freed again. Resolve the circularity by holding a weak reference to the bo from the cache side. This is done by having the .pin callbacks not bump the bo's refcount -- instead the common Host1x bo code does so, except for the cache reference. Also move the remove-cache-mapping-on-free code into a common function inside Host1x code. This is only called from the TegraDRM GEM buffers since those are the only ones that can be cached at the moment. | |
| Title | gpu: host1x: Allow entries in BO caches to be freed | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-15T05:58:58.354Z
Reserved: 2026-08-15T05:44:03.890Z
Link: CVE-2026-74381
No data.
Status : Received
Published: 2026-08-15T06:22:39.927
Modified: 2026-08-15T06:22:39.927
Link: CVE-2026-74381
No data.
OpenCVE Enrichment
Updated: 2026-08-15T13:30:04Z