CVE-2024-26803

net: veth: clear GRO when clearing XDP even when down

Published Apr 4, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

net: veth: clear GRO when clearing XDP even when down

veth sets NETIF_F_GRO automatically when XDP is enabled,
because both features use the same NAPI machinery.

The logic to clear NETIF_F_GRO sits in veth_disable_xdp() which
is called both on ndo_stop and when XDP is turned off.
To avoid the flag from being cleared when the device is brought
down, the clearing is skipped when IFF_UP is not set.
Bringing the device down should indeed not modify its features.

Unfortunately, this means that clearing is also skipped when
XDP is disabled _while_ the device is down. And there's nothing
on the open path to bring the device features back into sync.
IOW if user enables XDP, disables it and then brings the device
up we'll end up with a stray GRO flag set but no NAPI instances.

We don't depend on the GRO flag on the datapath, so the datapath
won't crash. We will crash (or hang), however, next time features
are sync'ed (either by user via ethtool or peer changing its config).
The GRO flag will go away, and veth will try to disable the NAPIs.
But the open path never created them since XDP was off, the GRO flag
was a stray. If NAPI was initialized before we'll hang in napi_disable().
If it never was we'll crash trying to stop uninitialized hrtimer.

Move the GRO flag updates to the XDP enable / disable paths,
instead of mixing them with the ndo_open / ndo_close paths.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-5658-1 linux security update
Ubuntu USN Ubuntu USN USN-6820-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6820-2 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-4 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-6828-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6871-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6892-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6900-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6919-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-459
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 11, 2026, 8:04 PM
Reserved
Feb 19, 2024, 2:20 PM
Status
Analyzed
Published
Apr 4, 2024, 9:15 AM
Modified
Jun 17, 2026, 7:18 AM
Severity
Low
Public date
Apr 4, 2024, 12:00 AM