CVE-2024-43889 padata: Fix possible divide-by-0 panic in padata_mt_helper()

2024-08-2610:10:42

Linux

www.cve.org

linux kernel

padata

divide-by-0 panic

EPSS

Percentile

5.0%

JSON

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

padata: Fix possible divide-by-0 panic in padata_mt_helper()

We are hit with a not easily reproducible divide-by-0 panic in padata.c at
bootup time.

[ 10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI
[ 10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1
[ 10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021
[ 10.017908] Workqueue: events_unbound padata_mt_helper
[ 10.017908] RIP: 0010:padata_mt_helper+0x39/0xb0
:
[ 10.017963] Call Trace:
[ 10.017968] <TASK>
[ 10.018004] ? padata_mt_helper+0x39/0xb0
[ 10.018084] process_one_work+0x174/0x330
[ 10.018093] worker_thread+0x266/0x3a0
[ 10.018111] kthread+0xcf/0x100
[ 10.018124] ret_from_fork+0x31/0x50
[ 10.018138] ret_from_fork_asm+0x1a/0x30
[ 10.018147] </TASK>

Looking at the padata_mt_helper() function, the only way a divide-by-0
panic can happen is when ps->chunk_size is 0. The way that chunk_size is
initialized in padata_do_multithreaded(), chunk_size can be 0 when the
min_chunk in the passed-in padata_mt_job structure is 0.

Fix this divide-by-0 panic by making sure that chunk_size will be at least
1 no matter what the input parameters are.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "kernel/padata.c"
    ],
    "versions": [
      {
        "version": "004ed42638f4",
        "lessThan": "ab8b397d5997",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "004ed42638f4",
        "lessThan": "8f5ffd2af727",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "004ed42638f4",
        "lessThan": "a29cfcb848c3",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "004ed42638f4",
        "lessThan": "924f788c906d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "004ed42638f4",
        "lessThan": "da0ffe84fcc1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "004ed42638f4",
        "lessThan": "6d45e1c948a8",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "kernel/padata.c"
    ],
    "versions": [
      {
        "version": "5.8",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.8",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.224",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.165",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.105",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.46",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10.5",
        "lessThanOrEqual": "6.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.11",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]