CVE-2021-47305: dma-buf/sync_file: Don't leak fences on merge failure
Vulnerability summary
CVE-2021-47305 is a medium (CVSS 5.5) Reachable Assertion vulnerability in linux. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 14.9% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 6 · Related 6Timeline
- 21-05-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: dma-buf/sync_file: Don't leak fences on merge failure Each add_fence() call does a dma_fence_get() on the relevant fence. In the error path, we weren't calling dma_fence_put() so all those fences got leaked. Also, in the krealloc_array failure case, we weren't freeing the fences array. Instead, ensure that i and fences are always zero-initialized and dma_fence_put() all the fences and kfree(fences) on every error path.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.24%
Chance of exploitation in the next 30 days
Percentile
15%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.24% 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 causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu86 products
- linux< 4.15.0-159.167 | < 5.4.0-88.99
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 4.15.0-1112.119 | < 5.4.0-1057.60
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ a02b9dc90d844cc7df7b63264e7920cc425052d9, < 19f51c2529339280d2c8c6427cd3e21ddf1ac3f8 | ≥ a02b9dc90d844cc7df7b63264e7920cc425052d9, < e0355a0ad31a1d677b2a4514206de4902bd550e8 | ≥ a02b9dc90d844cc7df7b63264e7920cc425052d9, < 41f45e91c92c8480242ea448d54e28c753b13902 | ≥ a02b9dc90d844cc7df7b63264e7920cc425052d9, < 0d514185ae792d3a1903c8e1a83899aa996705ce | ≥ a02b9dc90d844cc7df7b63264e7920cc425052d9, < 19edcd97727aae9362444a859a24d99a8730cb27 | ≥ a02b9dc90d844cc7df7b63264e7920cc425052d9, < ffe000217c5068c5da07ccb1c0f8cce7ad767435 | 4.9
- linux_kernel≥ 4.9, < 4.14.241 | ≥ 4.15, < 4.19.199 | ≥ 4.20, < 5.4.135 | ≥ 5.5, < 5.10.53 | ≥ 5.11, < 5.13.5 | 5.14:rc1
Debian1 product
- linux< 5.14.6-1
3 vendors · 89 products
