CVE-2024-26803

2024-04-0409:15:09

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

veth

xdp

vulnerability

napi

gro

features

ndo_stop

ndo_close

iff_up.

6.4 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.7%

JSON

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.

Affected configurations

Vulners

Node

linuxlinux_kernelRange5.13–5.15.151

linuxlinux_kernelRange5.16.0–6.1.81

linuxlinux_kernelRange6.2.0–6.6.21

linuxlinux_kernelRange6.7.0–6.7.9

linuxlinux_kernelRange6.8.0≥

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/veth.c"
    ],
    "versions": [
      {
        "version": "d3256efd8e8b",
        "lessThan": "f011c103e654",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d3256efd8e8b",
        "lessThan": "7985d73961bb",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d3256efd8e8b",
        "lessThan": "16edf51f33f5",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d3256efd8e8b",
        "lessThan": "8f7a3894e58e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d3256efd8e8b",
        "lessThan": "fe9f801355f0",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/veth.c"
    ],
    "versions": [
      {
        "version": "5.13",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.13",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.151",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.81",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.21",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.7.9",
        "lessThanOrEqual": "6.7.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]