CVE-2021-47542: net: qlogic: qlcnic: Fix a NULL pointer dereference in qlcnic_83xx_add_rings()
Vulnerability summary
CVE-2021-47542 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.5% 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 12 · Related 12Timeline
- 24-05-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: net: qlogic: qlcnic: Fix a NULL pointer dereference in qlcnic_83xx_add_rings() In qlcnic_83xx_add_rings(), the indirect function of ahw->hw_ops->alloc_mbx_args will be called to allocate memory for cmd.req.arg, and there is a dereference of it in qlcnic_83xx_add_rings(), which could lead to a NULL pointer dereference on failure of the indirect function like qlcnic_83xx_alloc_mbx_args(). Fix this bug by adding a check of alloc_mbx_args(), this patch imitates the logic of mbx_cmd()'s failure handling. 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_QLCNIC=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
0.25%
Chance of exploitation in the next 30 days
Percentile
17%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.25% 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.
Ubuntu88 products
- linuxAll versions (No fix recorded) | < 4.4.0-258.292 | < 4.15.0-169.177 | < 5.4.0-100.113
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 4.4.0-1135.141 | < 4.4.0-1173.188 | < 4.15.0-1121.129 | < 5.4.0-1066.69
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 7f9664525f9cb507de9198a395a111371413f230, < 3a061d54e260b701b538873b43e399d9b8b83e03 | ≥ 7f9664525f9cb507de9198a395a111371413f230, < b4f217d6fcc00c3fdc0921a7691f30be7490b073 | ≥ 7f9664525f9cb507de9198a395a111371413f230, < 550658a2d61e4eaf522c8ebc7fad76dc376bfb45 | ≥ 7f9664525f9cb507de9198a395a111371413f230, < 57af54a56024435d83e44c78449513b414eb6edf | ≥ 7f9664525f9cb507de9198a395a111371413f230, < bbeb0325a7460ebf1e03f5e0bfc5c652fba9519f | ≥ 7f9664525f9cb507de9198a395a111371413f230, < 15fa12c119f869173f9b710cbe6a4a14071d2105 | ≥ 7f9664525f9cb507de9198a395a111371413f230, < c5ef33c1489b2cd74368057fa00b5d2183bb5853 | ≥ 7f9664525f9cb507de9198a395a111371413f230, < e2dabc4f7e7b60299c20a36d6a7b24ed9bf8e572 | 3.9
- linux_kernel≥ 3.9, < 4.4.294 | ≥ 4.5, < 4.9.292 | ≥ 4.10, < 4.14.257 | ≥ 4.15, < 4.19.220 | ≥ 4.20, < 5.4.164 | ≥ 5.5, < 5.10.84 | ≥ 5.11, < 5.15.7
Debian1 product
- linux< 5.15.15-1
3 vendors · 91 products
