CVE-2024-35895

2024-05-1909:15:10

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

web.nvd.nist.gov

linux

kernel

vulnerability

patch

lock inversion

deadlock

map delete elem

sockmap

sockhash

bpf

tracing program

interrupts

6.6 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

10.4%

JSON

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

bpf, sockmap: Prevent lock inversion deadlock in map delete elem

syzkaller started using corpuses where a BPF tracing program deletes
elements from a sockmap/sockhash map. Because BPF tracing programs can be
invoked from any interrupt context, locks taken during a map_delete_elem
operation must be hardirq-safe. Otherwise a deadlock due to lock inversion
is possible, as reported by lockdep:

   CPU0                    CPU1
   ----                    ----

lock(&htab->buckets[i].lock);
local_irq_disable();
lock(&host->lock);
lock(&htab->buckets[i].lock);
<Interrupt>
lock(&host->lock);

Locks in sockmap are hardirq-unsafe by design. We expects elements to be
deleted from sockmap/sockhash only in task (normal) context with interrupts
enabled, or in softirq context.

Detect when map_delete_elem operation is invoked from a context which is
not hardirq-unsafe, that is interrupts are disabled, and bail out with an
error.

Note that map updates are not affected by this issue. BPF verifier does not
allow updating sockmap/sockhash from a BPF tracing program today.

Affected configurations

Vulners

Node

linuxlinux_kernelRange4.20–5.4.274

linuxlinux_kernelRange5.5.0–5.10.215

linuxlinux_kernelRange5.11.0–5.15.154

linuxlinux_kernelRange5.16.0–6.1.85

linuxlinux_kernelRange6.2.0–6.6.26

linuxlinux_kernelRange6.7.0–6.8.5

linuxlinux_kernelRange6.9.0≥

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/core/sock_map.c"
    ],
    "versions": [
      {
        "version": "604326b41a6f",
        "lessThan": "f7990498b05a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "604326b41a6f",
        "lessThan": "dd54b48db0c8",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "604326b41a6f",
        "lessThan": "d1e73fb19a4c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "604326b41a6f",
        "lessThan": "a44770fed865",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "604326b41a6f",
        "lessThan": "668b3074aa14",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "604326b41a6f",
        "lessThan": "6af057ccdd8e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "604326b41a6f",
        "lessThan": "ff9105993240",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/core/sock_map.c"
    ],
    "versions": [
      {
        "version": "4.20",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "4.20",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.274",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.215",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.154",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.85",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.26",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.5",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]