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btrfs: fix use-after-free after failure to create a snapshot

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free after failure to create a snapshot At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and then attach it to the transaction's list of pending snapshots. After that we call btrfs_commit_transaction(), and if that returns an error we jump to 'fail' label, where we kfree() the pending snapshot structure. This can result in a later use-after-free of the pending snapshot: 1) We allocated the pending snapshot and added it to the transaction's list of pending snapshots; 2) We call btrfs_commit_transaction(), and it fails either at the first call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups(). In both cases, we don't abort the transaction and we release our transaction handle. We jump to the 'fail' label and free the pending snapshot structure. We return with the pending snapshot still in the transaction's list; 3) Another task commits the transaction. This time there's no error at all, and then during the transaction commit it accesses a pointer to the pending snapshot structure that the snapshot creation task has already freed, resulting in a user-after-free. This issue could actually be detected by smatch, which produced the following warning: fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list So fix this by not having the snapshot creation ioctl directly add the pending snapshot to the transaction's list. Inst

Products
Kernel
Affected versions
Not specified
Fixed versions
5.10.226, 5.15.22, 5.16.8
CVEs
CVE-2022-48733
Confirmed fixed CVEs
Not specified
Updated in this feed
5 Nov 2026, 02:01 UTC · Revision 1

Source evidence

btrfs: fix use-after-free after failure to create a snapshot

core-osv · Original source

Published 20 Jun 2024, 11:13 UTC

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free after failure to create a snapshot At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and then attach it to the transaction's list of pending snapshots. After that we call btrfs_commit_transaction(), and if that returns an error we jump to 'fail' label, where we kfree() the pending snapshot structure. This can result in a later use-after-free of the pending snapshot: 1) We allocated the pending snapshot and added it to the transaction's list of pending snapshots; 2) We call btrfs_commit_transaction(), and it fails either at the first call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups(). In both cases, we don't abort the transaction and we release our transaction handle. We jump to the 'fail' label and free the pending snapshot structure. We return with the pending snapshot still in the transaction's list; 3) Another task commits the transaction. This time there's no error at all, and then during the transaction commit it accesses a pointer to the pending snapshot structure that the snapshot creation task has already freed, resulting in a user-after-free. This issue could actually be detected by smatch, which produced the following warning: fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list So fix this by not having the snapshot creation ioctl directly add the pending snapshot to the transaction's list. Inst

osv:CVE-2022-48733

Kernel

Fixed versions: 5.10.226, 5.15.22, 5.16.8

Complete source record
{
  "id": "2992188e69bee3f3b185a35546229b7ffe278b5302c0749c96fd2e0e5ece5a96",
  "url": "https://osv.dev/vulnerability/CVE-2022-48733",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "btrfs: fix use-after-free after failure to create a snapshot",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free after failure to create a snapshot At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and then attach it to the transaction's list of pending snapshots. After that we call btrfs_commit_transaction(), and if that returns an error we jump to 'fail' label, where we kfree() the pending snapshot structure. This can result in a later use-after-free of the pending snapshot: 1) We allocated the pending snapshot and added it to the transaction's list of pending snapshots; 2) We call btrfs_commit_transaction(), and it fails either at the first call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups(). In both cases, we don't abort the transaction and we release our transaction handle. We jump to the 'fail' label and free the pending snapshot structure. We return with the pending snapshot still in the transaction's list; 3) Another task commits the transaction. This time there's no error at all, and then during the transaction commit it accesses a pointer to the pending snapshot structure that the snapshot creation task has already freed, resulting in a user-after-free. This issue could actually be detected by smatch, which produced the following warning: fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list So fix this by not having the snapshot creation ioctl directly add the pending snapshot to the transaction's list. Inst",
    "evidence": "osv:CVE-2022-48733",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.226",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.22",
            "evidence": "/affected/1/ranges"
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          {
            "value": "5.16.8",
            "evidence": "/affected/1/ranges"
          }
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        "affected_versions": []
      }
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    "severity": "high",
    "structured": {
      "id": "CVE-2022-48733",
      "aliases": [
        "CVE-2022-48733"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
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      "affected": [
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        {
          "ranges": [
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              "type": "ECOSYSTEM",
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          "package": {
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            "ecosystem": "Linux"
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          "database_specific": {
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          }
        }
      ],
      "modified": "2026-10-28T02:30:41.655513339Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/28b21c558a3753171097193b6f6602a94169093a",
        "https://git.kernel.org/stable/c/7e4c72dbaf62f8978af8321a24dbd35566d3a78a",
        "https://git.kernel.org/stable/c/9372fa1d73da5f1673921e365d0cd2c27ec7adc2",
        "https://git.kernel.org/stable/c/a7b717fa15165d3d9245614680bebc48a52ac05d",
        "https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48733.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2022-48733",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48733.json"
      }
    },
    "related_cves": [
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        "value": "CVE-2022-48733",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 509304,
  "published_at": "2024-06-20T11:13:20.737+00:00"
}