ghsa-3rvw-7pxp-g8xm
Vulnerability from github
Published
2024-10-21 18:30
Modified
2024-11-08 18:30
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Details

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

fbdev: pxafb: Fix possible use after free in pxafb_task()

In the pxafb_probe function, it calls the pxafb_init_fbinfo function, after which &fbi->task is associated with pxafb_task. Moreover, within this pxafb_init_fbinfo function, the pxafb_blank function within the &pxafb_ops struct is capable of scheduling work.

If we remove the module which will call pxafb_remove to make cleanup, it will call unregister_framebuffer function which can call do_unregister_framebuffer to free fbi->fb through put_fb_info(fb_info), while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows:

CPU0 CPU1

                               | pxafb_task

pxafb_remove | unregister_framebuffer(info) | do_unregister_framebuffer(fb_info) | put_fb_info(fb_info) | // free fbi->fb | set_ctrlr_state(fbi, state) | __pxafb_lcd_power(fbi, 0) | fbi->lcd_power(on, &fbi->fb.var) | //use fbi->fb

Fix it by ensuring that the work is canceled before proceeding with the cleanup in pxafb_remove.

Note that only root user can remove the driver at runtime.

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2024-49924"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-10-21T18:15:14Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: pxafb: Fix possible use after free in pxafb_task()\n\nIn the pxafb_probe function, it calls the pxafb_init_fbinfo function,\nafter which \u0026fbi-\u003etask is associated with pxafb_task. Moreover,\nwithin this pxafb_init_fbinfo function, the pxafb_blank function\nwithin the \u0026pxafb_ops struct is capable of scheduling work.\n\nIf we remove the module which will call pxafb_remove to make cleanup,\nit will call unregister_framebuffer function which can call\ndo_unregister_framebuffer to free fbi-\u003efb through\nput_fb_info(fb_info), while the work mentioned above will be used.\nThe sequence of operations that may lead to a UAF bug is as follows:\n\nCPU0                                                CPU1\n\n                                   | pxafb_task\npxafb_remove                       |\nunregister_framebuffer(info)       |\ndo_unregister_framebuffer(fb_info) |\nput_fb_info(fb_info)               |\n// free fbi-\u003efb                    | set_ctrlr_state(fbi, state)\n                                   | __pxafb_lcd_power(fbi, 0)\n                                   | fbi-\u003elcd_power(on, \u0026fbi-\u003efb.var)\n                                   | //use fbi-\u003efb\n\nFix it by ensuring that the work is canceled before proceeding\nwith the cleanup in pxafb_remove.\n\nNote that only root user can remove the driver at runtime.",
  "id": "GHSA-3rvw-7pxp-g8xm",
  "modified": "2024-11-08T18:30:45Z",
  "published": "2024-10-21T18:30:58Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-49924"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3c0d416eb4bef705f699213cee94bf54b6acdacd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4a6921095eb04a900e0000da83d9475eb958e61e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4cda484e584be34d55ee17436ebf7ad11922b97a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6d0a07f68b66269e167def6c0b90a219cd3e7473"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a3a855764dbacbdb1cc51e15dc588f2d21c93e0e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aaadc0cb05c999ccd8898a03298b7e5c31509b08"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e657fa2df4429f3805a9b3e47fb1a4a1b02a72bd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e6897e299f57b103e999e62010b88e363b3eebae"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fdda354f60a576d52dcf90351254714681df4370"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}


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