CVE-2023-53501: iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind
Vulnerability summary
CVE-2023-53501 is a medium (CVSS 4.7) vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.1% of scored vulnerabilities.
Not severe (CVSS 4.7, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 12 · Related 10Timeline
- 01-10-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated4.7MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated4.7MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.15%
Chance of exploitation in the next 30 days
Percentile
4%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.15% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu111 products
- linux< 5.15.0-94.104
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1053.58
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 8bc54824da4e8fcf0ed679cf09ac32f23d83254a, < a50d60b8f2aff46dd7c7edb4a5835cdc4d432c22 | ≥ 8bc54824da4e8fcf0ed679cf09ac32f23d83254a, < 13ed255248dfbbb7f23f9170c7a537fb9ca22c73 | ≥ 8bc54824da4e8fcf0ed679cf09ac32f23d83254a, < 9ccc51be3126b25cfe9351dbffde946c925cc28a | ≥ 8bc54824da4e8fcf0ed679cf09ac32f23d83254a, < 98d86bf32187db27946ca817c2467a5f2f7aa02f | ≥ 8bc54824da4e8fcf0ed679cf09ac32f23d83254a, < 534103bcd52ca9c1fecbc70e717b4a538dc4ded8 | 5.15
- linux_kernel≥ 5.15, < 5.15.132 | ≥ 5.16, < 6.1.53 | ≥ 6.2, < 6.4.16 | ≥ 6.5, < 6.5.3
Debian1 product
- linux< 6.1.55-1 | < 6.5.3-1
3 vendors · 114 products
