Improper Locking Affecting kernel-rt-debug-kvm package, versions *


Severity

Recommended
0.0
medium
0
10

Based on CentOS security rating

    Threat Intelligence

    EPSS
    0.04% (6th percentile)

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  • Snyk ID SNYK-CENTOS8-KERNELRTDEBUGKVM-7760683
  • published 21 Aug 2024
  • disclosed 17 Aug 2024

How to fix?

There is no fixed version for Centos:8 kernel-rt-debug-kvm.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug-kvm package and not the kernel-rt-debug-kvm package as distributed by Centos. See How to fix? for Centos:8 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

virtio_net: Fix napi_skb_cache_put warning

After the commit bdacf3e34945 ("net: Use nested-BH locking for napi_alloc_cache.") was merged, the following warning began to appear:

 WARNING: CPU: 5 PID: 1 at net/core/skbuff.c:1451 napi_skb_cache_put+0x82/0x4b0

__warn+0x12f/0x340 napi_skb_cache_put+0x82/0x4b0 napi_skb_cache_put+0x82/0x4b0 report_bug+0x165/0x370 handle_bug+0x3d/0x80 exc_invalid_op+0x1a/0x50 asm_exc_invalid_op+0x1a/0x20 __free_old_xmit+0x1c8/0x510 napi_skb_cache_put+0x82/0x4b0 __free_old_xmit+0x1c8/0x510 __free_old_xmit+0x1c8/0x510 __pfx___free_old_xmit+0x10/0x10

The issue arises because virtio is assuming it's running in NAPI context even when it's not, such as in the netpoll case.

To resolve this, modify virtnet_poll_tx() to only set NAPI when budget is available. Same for virtnet_poll_cleantx(), which always assumed that it was in a NAPI context.

CVSS Scores

version 3.1
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NVD

5.5 medium
  • Attack Vector (AV)
    Local
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    Low
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    None
  • Integrity (I)
    None
  • Availability (A)
    High
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Red Hat

5.5 medium
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SUSE

5.5 medium