NULL pointer dereference in Linux

CVE-2021-47528

In the Linux kernel, the following vulnerability has been resolved: usb: cdnsp: Fix a NULL pointer dereference in cdnsp_endpoint_init() In cdnsp_endpoint_init(), cdnsp_ring_alloc() is assigned to pep->ring and there is a dereference of it in cdnsp_endpoint_init(), which could lead to a NULL pointer dereference on failure of cdnsp_ring_alloc(). Fix this bug by adding a check of pep->ring. 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_USB_CDNSP_GADGET=y show no new warnings, and our static analyzer no longer warns about this code.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (9.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-47528: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47528?
CVE-2021-47528 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2024-05-24.
How severe is CVE-2021-47528?
Medium severity. CVSS v3 base score is 5.5 out of 10.