CVE-2023-53501
Published: October 2, 2025Last modified: October 2, 2025
Description
In the Linux kernel, the following vulnerability has been resolved: iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind When unbinding pasid - a race condition exists vs outstanding page faults. To prevent this, the pasid_state object contains a refcount. * set to 1 on pasid bind * incremented on each ppr notification start * decremented on each ppr notification done * decremented on pasid unbind Since refcount_dec assumes that refcount will never reach 0: the current implementation causes the following to be invoked on pasid unbind: REFCOUNT_WARN("decrement hit 0; leaking memory") Fix this issue by changing refcount_dec to refcount_dec_and_test to explicitly handle refcount=1.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 4.7 |
| Attack Vector | LOCAL |
| Attack complexity | HIGH |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.53-r0) |
| 25 LTS | linux-lts | Not affected (6.6.89-r0) | |
| Stream | linux-lts | Fixed (6.6.58-r0) |
References
- https://git.kernel.org/stable/c/13ed255248dfbbb7f23f9170c7a537fb9ca22c73
- https://git.kernel.org/stable/c/534103bcd52ca9c1fecbc70e717b4a538dc4ded8
- https://git.kernel.org/stable/c/98d86bf32187db27946ca817c2467a5f2f7aa02f
- https://git.kernel.org/stable/c/9ccc51be3126b25cfe9351dbffde946c925cc28a
- https://git.kernel.org/stable/c/a50d60b8f2aff46dd7c7edb4a5835cdc4d432c22