{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2021-46958",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-46958",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-02-27T18:46:59.315Z",
    "updatedAt": "2026-08-05T08:45:13.853Z",
    "importedAt": "2026-10-24T01:56:36.661Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "btrfs: fix race between transaction aborts and fsyncs leading to use-after-free",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix race between transaction aborts and fsyncs leading to use-after-free\n\nThere is a race between a task aborting a transaction during a commit,\na task doing an fsync and the transaction kthread, which leads to an\nuse-after-free of the log root tree. When this happens, it results in a\nstack trace like the following:\n\n  BTRFS info (device dm-0): forced readonly\n  BTRFS warning (device dm-0): Skipping commit of aborted transaction.\n  BTRFS: error (device dm-0) in cleanup_transaction:1958: errno=-5 IO failure\n  BTRFS warning (device dm-0): lost page write due to IO error on /dev/mapper/error-test (-5)\n  BTRFS warning (device dm-0): Skipping commit of aborted transaction.\n  BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0xa4e8 len 4096 err no 10\n  BTRFS error (device dm-0): error writing primary super block to device 1\n  BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e000 len 4096 err no 10\n  BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e008 len 4096 err no 10\n  BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e010 len 4096 err no 10\n  BTRFS: error (device dm-0) in write_all_supers:4110: errno=-5 IO failure (1 errors while writing supers)\n  BTRFS: error (device dm-0) in btrfs_sync_log:3308: errno=-5 IO failure\n  general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b68: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI\n  CPU: 2 PID: 2458471 Comm: fsstress Not tainted 5.12.0-rc5-btrfs-next-84 #1\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014\n  RIP: 0010:__mutex_lock+0x139/0xa40\n  Code: c0 74 19 (...)\n  RSP: 0018:ffff9f18830d7b00 EFLAGS: 00010202\n  RAX: 6b6b6b6b6b6b6b68 RBX: 0000000000000001 RCX: 0000000000000002\n  RDX: ffffffffb9c54d13 RSI: 0000000000000000 RDI: 0000000000000000\n  RBP: ffff9f18830d7bc0 R08: 0000000000000000 R09: 0000000000000000\n  R10: ffff9f18830d7be0 R11: 0000000000000001 R12: ffff8c6cd199c040\n  R13: ffff8c6c95821358 R14: 00000000fffffffb R15: ffff8c6cbcf01358\n  FS:  00007fa9140c2b80(0000) GS:ffff8c6fac600000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007fa913d52000 CR3: 000000013d2b4003 CR4: 0000000000370ee0\n  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n  Call Trace:\n   ? __btrfs_handle_fs_error+0xde/0x146 [btrfs]\n   ? btrfs_sync_log+0x7c1/0xf20 [btrfs]\n   ? btrfs_sync_log+0x7c1/0xf20 [btrfs]\n   btrfs_sync_log+0x7c1/0xf20 [btrfs]\n   btrfs_sync_file+0x40c/0x580 [btrfs]\n   do_fsync+0x38/0x70\n   __x64_sys_fsync+0x10/0x20\n   do_syscall_64+0x33/0x80\n   entry_SYSCALL_64_after_hwframe+0x44/0xae\n  RIP: 0033:0x7fa9142a55c3\n  Code: 8b 15 09 (...)\n  RSP: 002b:00007fff26278d48 EFLAGS: 00000246 ORIG_RAX: 000000000000004a\n  RAX: ffffffffffffffda RBX: 0000563c83cb4560 RCX: 00007fa9142a55c3\n  RDX: 00007fff26278cb0 RSI: 00007fff26278cb0 RDI: 0000000000000005\n  RBP: 0000000000000005 R08: 0000000000000001 R09: 00007fff26278d5c\n  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000340\n  R13: 00007fff26278de0 R14: 00007fff26278d96 R15: 0000563c83ca57c0\n  Modules linked in: btrfs dm_zero dm_snapshot dm_thin_pool (...)\n  ---[ end trace ee2f1b19327d791d ]---\n\nThe steps that lead to this crash are the following:\n\n1) We are at transaction N;\n\n2) We have two tasks with a transaction handle attached to transaction N.\n   Task A and Task B. Task B is doing an fsync;\n\n3) Task B is at btrfs_sync_log(), and has saved fs_info->log_root_tree\n   into a local variable named 'log_root_tree' at the top of\n   btrfs_sync_log(). Task B is about to call write_all_supers(), but\n   before that...\n\n4) Task A calls btrfs_commit_transaction(), and after it sets the\n   transaction state to TRANS_STATE_COMMIT_START, an error happens before\n   it w\n---truncated---",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "ef67963dac255b293e19815ea3d440567be4626f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a4794be7b00b7eda4b45fffd283ab7d76df7e5d6"
            },
            {
              "version": "ef67963dac255b293e19815ea3d440567be4626f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "633f7f216663587f17601eaa1cf2ac3d5654874c"
            },
            {
              "version": "ef67963dac255b293e19815ea3d440567be4626f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e2da98788369bfba1138bada72765c47989a4338"
            },
            {
              "version": "ef67963dac255b293e19815ea3d440567be4626f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "061dde8245356d8864d29e25207aa4daa0be4d3c"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.7",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.7"
            },
            {
              "version": "5.10.36",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.11.20",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.11.*"
            },
            {
              "version": "5.12.3",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.12.*"
            },
            {
              "version": "5.13",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}