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blk-cgroup: Fix UAF in blkcg_unpin_online()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: Fix UAF in blkcg_unpin_online() blkcg_unpin_online() walks up the blkcg hierarchy putting the online pin. To walk up, it uses blkcg_parent(blkcg) but it was calling that after blkcg_destroy_blkgs(blkcg) which could free the blkcg, leading to the following UAF: ================================================================== BUG: KASAN: slab-use-after-free in blkcg_unpin_online+0x15a/0x270 Read of size 8 at addr ffff8881057678c0 by task kworker/9:1/117 CPU: 9 UID: 0 PID: 117 Comm: kworker/9:1 Not tainted 6.13.0-rc1-work-00182-gb8f52214c61a-dirty #48 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022 Workqueue: cgwb_release cgwb_release_workfn Call Trace: dump_stack_lvl+0x27/0x80 print_report+0x151/0x710 kasan_report+0xc0/0x100 blkcg_unpin_online+0x15a/0x270 cgwb_release_workfn+0x194/0x480 process_scheduled_works+0x71b/0xe20 worker_thread+0x82a/0xbd0 kthread+0x242/0x2c0 ret_from_fork+0x33/0x70 ret_from_fork_asm+0x1a/0x30 ... Freed by task 1944: kasan_save_track+0x2b/0x70 kasan_save_free_info+0x3c/0x50 __kasan_slab_free+0x33/0x50 kfree+0x10c/0x330 css_free_rwork_fn+0xe6/0xb30 process_scheduled_works+0x71b/0xe20 worker_thread+0x82a/0xbd0 kthread+0x242/0x2c0 ret_from_fork+0x33/0x70 ret_from_fork_asm+0x1a/0x30 Note that the UAF is not easy to trigger as the free path is indirected behind a couple RCU grace periods and a work item execution. I could only trigger it with arti

Announced Source revision 1
Original source ↗

CVE-2024-56672

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2024-56672

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4308a434e5e08c78676aa66bc626ef78cbef0883",
        "lessThan": "83f5a87ee8caa76a917f59912a74d6811f773c67",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "4308a434e5e08c78676aa66bc626ef78cbef0883",
        "lessThan": "8a07350fe070017a887433f4d6909433955be5f1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "4308a434e5e08c78676aa66bc626ef78cbef0883",
        "lessThan": "64afc6fe24c9896c0153e5a199bcea241ecb0d5c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "4308a434e5e08c78676aa66bc626ef78cbef0883",
        "lessThan": "5baa28569c924d9a90d036c2aaab79f791fedaf8",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "4308a434e5e08c78676aa66bc626ef78cbef0883",
        "lessThan": "29d1e06560f0f6179062ac638b4064deb637d1ad",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "4308a434e5e08c78676aa66bc626ef78cbef0883",
        "lessThan": "86e6ca55b83c575ab0f2e105cf08f98e58d3d7af",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "block/blk-cgroup.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.7"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.7",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.234",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.177",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.121",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.67",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.6",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.13",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "block/blk-cgroup.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2024-56672

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#26838 · Revision 1
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Publisher date
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