CVE-2021-47556
Severity CVSS v4.0:
Pending analysis
Type:
CWE-476
NULL Pointer Dereference
Publication date:
24/05/2024
Last modified:
10/06/2024
Description
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
ethtool: ioctl: fix potential NULL deref in ethtool_set_coalesce()<br />
<br />
ethtool_set_coalesce() now uses both the .get_coalesce() and<br />
.set_coalesce() callbacks. But the check for their availability is<br />
buggy, so changing the coalesce settings on a device where the driver<br />
provides only _one_ of the callbacks results in a NULL pointer<br />
dereference instead of an -EOPNOTSUPP.<br />
<br />
Fix the condition so that the availability of both callbacks is<br />
ensured. This also matches the netlink code.<br />
<br />
Note that reproducing this requires some effort - it only affects the<br />
legacy ioctl path, and needs a specific combination of driver options:<br />
- have .get_coalesce() and .coalesce_supported but no<br />
.set_coalesce(), or<br />
- have .set_coalesce() but no .get_coalesce(). Here eg. ethtool doesn&#39;t<br />
cause the crash as it first attempts to call ethtool_get_coalesce()<br />
and bails out on error.
Impact
Base Score 3.x
5.50
Severity 3.x
MEDIUM
Vulnerable products and versions
CPE | From | Up to |
---|---|---|
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.15 (including) | 5.15.6 (excluding) |
To consult the complete list of CPE names with products and versions, see this page