ghsa-7h7v-xpwq-j3w4
Vulnerability from github
Published
2024-05-21 18:31
Modified
2024-12-30 21:30
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Details

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

cxl/mem: Fix shutdown order

Ira reports that removing cxl_mock_mem causes a crash with the following trace:

BUG: kernel NULL pointer dereference, address: 0000000000000044 [..] RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core] [..] Call Trace: cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x29/0x40 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 device_unregister+0x13/0x60 devm_release_action+0x4d/0x90 ? __pfx_unregister_port+0x10/0x10 [cxl_core] delete_endpoint+0x121/0x130 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 ? lock_release+0x142/0x290 cdev_device_del+0x15/0x50 cxl_memdev_unregister+0x54/0x70 [cxl_core]

This crash is due to the clearing out the cxl_memdev's driver context (@cxlds) before the subsystem is done with it. This is ultimately due to the region(s), that this memdev is a member, being torn down and expecting to be able to de-reference @cxlds, like here:

static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) ... if (cxlds->rcd) goto endpoint_reset; ...

Fix it by keeping the driver context valid until memdev-device unregistration, and subsequently the entire stack of related dependencies, unwinds.

Show details on source website

To clipboard 

{
   affected: [],
   aliases: [
      "CVE-2023-52849",
   ],
   database_specific: {
      cwe_ids: [
         "CWE-476",
      ],
      github_reviewed: false,
      github_reviewed_at: null,
      nvd_published_at: "2024-05-21T16:15:22Z",
      severity: "MODERATE",
   },
   details: "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mem: Fix shutdown order\n\nIra reports that removing cxl_mock_mem causes a crash with the following\ntrace:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000044\n [..]\n RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core]\n [..]\n Call Trace:\n  <TASK>\n  cxl_region_detach+0xe8/0x210 [cxl_core]\n  cxl_decoder_kill_region+0x27/0x40 [cxl_core]\n  cxld_unregister+0x29/0x40 [cxl_core]\n  devres_release_all+0xb8/0x110\n  device_unbind_cleanup+0xe/0x70\n  device_release_driver_internal+0x1d2/0x210\n  bus_remove_device+0xd7/0x150\n  device_del+0x155/0x3e0\n  device_unregister+0x13/0x60\n  devm_release_action+0x4d/0x90\n  ? __pfx_unregister_port+0x10/0x10 [cxl_core]\n  delete_endpoint+0x121/0x130 [cxl_core]\n  devres_release_all+0xb8/0x110\n  device_unbind_cleanup+0xe/0x70\n  device_release_driver_internal+0x1d2/0x210\n  bus_remove_device+0xd7/0x150\n  device_del+0x155/0x3e0\n  ? lock_release+0x142/0x290\n  cdev_device_del+0x15/0x50\n  cxl_memdev_unregister+0x54/0x70 [cxl_core]\n\nThis crash is due to the clearing out the cxl_memdev's driver context\n(@cxlds) before the subsystem is done with it. This is ultimately due to\nthe region(s), that this memdev is a member, being torn down and expecting\nto be able to de-reference @cxlds, like here:\n\nstatic int cxl_region_decode_reset(struct cxl_region *cxlr, int count)\n...\n                if (cxlds->rcd)\n                        goto endpoint_reset;\n...\n\nFix it by keeping the driver context valid until memdev-device\nunregistration, and subsequently the entire stack of related\ndependencies, unwinds.",
   id: "GHSA-7h7v-xpwq-j3w4",
   modified: "2024-12-30T21:30:46Z",
   published: "2024-05-21T18:31:22Z",
   references: [
      {
         type: "ADVISORY",
         url: "https://nvd.nist.gov/vuln/detail/CVE-2023-52849",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/0ca074f7d788627a4e0b047ca5fbdb5fc567220c",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/20bd0198bebdd706bd4614b3933ef70d7c19618f",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/7c7371b41a14e86f53e7dbe5baa7b1d3e0ab324b",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/88d3917f82ed4215a2154432c26de1480a61b209",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/cad22a757029c3a1985c221a2d4a6491ad4035ae",
      },
   ],
   schema_version: "1.4.0",
   severity: [
      {
         score: "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
         type: "CVSS_V3",
      },
   ],
}


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