CVE-2021-4441: spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op()
Vulnerability summary
CVE-2021-4441 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 13.2% 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 7 · Related 7Timeline
- 22-08-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op() In zynq_qspi_exec_mem_op(), kzalloc() is directly used in memset(), which could lead to a NULL pointer dereference on failure of kzalloc(). Fix this bug by adding a check of tmpbuf. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_SPI_ZYNQ_QSPI=m show no new warnings, and our static analyzer no longer warns about this code.
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
0.22%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.22% 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.
Ubuntu95 products
- linux< 5.4.0-117.132
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.4.0-1078.84
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 67dca5e580f1e93a66177389981541cac208c817, < df14d2bed8e2455878e046e67123d9ecb2e79056 | ≥ 67dca5e580f1e93a66177389981541cac208c817, < 2efece1368aeee2d2552c7ec36aeb676c4d4c95f | ≥ 67dca5e580f1e93a66177389981541cac208c817, < 3c32405d6474a21f7d742828e73c13e326dcae82 | ≥ 67dca5e580f1e93a66177389981541cac208c817, < b9dd08cbebe0c593c49bf86d2012a431494e54cb | ≥ 67dca5e580f1e93a66177389981541cac208c817, < ab3824427b848da10e9fe2727f035bbeecae6ff4 | 5.2
- linux_kernel≥ 5.2, < 5.4.182 | ≥ 5.5, < 5.10.103 | ≥ 5.11, < 5.15.26 | ≥ 5.16, < 5.16.12 | 5.17:rc1 | 5.17:rc2 | 5.17:rc3 | 5.17:rc4 | 5.17:rc5
Debian1 product
- linux< 5.16.12-1
3 vendors · 98 products
