{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "908960c6c0fb3b3ce3971dc0ca47b581d256b968"
            },
            {
              "fixed": "f6df18c001e3dcebc08482d0adeacd0cfea08593"
            },
            {
              "fixed": "8ceaad6cd6e7fa5f73b0b2796a2e85d75d37e9f3"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.13.0"
            },
            {
              "fixed": "6.19.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43299.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure()\n\n[BUG]\nThere is a bug report that when btrfs hits ENOSPC error in a critical\npath, btrfs flips RO (this part is expected, although the ENOSPC bug\nstill needs to be addressed).\n\nThe problem is after the RO flip, if there is a read repair pending, we\ncan hit the ASSERT() inside btrfs_repair_io_failure() like the following:\n\n  BTRFS info (device vdc): relocating block group 30408704 flags metadata|raid1\n  ------------[ cut here ]------------\n  BTRFS: Transaction aborted (error -28)\n  WARNING: fs/btrfs/extent-tree.c:3235 at __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844\n  Modules linked in: kvm_intel kvm irqbypass\n  [...]\n  ---[ end trace 0000000000000000 ]---\n  BTRFS info (device vdc state EA): 2 enospc errors during balance\n  BTRFS info (device vdc state EA): balance: ended with status: -30\n  BTRFS error (device vdc state EA): parent transid verify failed on logical 30556160 mirror 2 wanted 8 found 6\n  BTRFS error (device vdc state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt 10, gen 0\n  [...]\n  assertion failed: !(fs_info-\u003esb-\u003es_flags \u0026 SB_RDONLY) :: 0, in fs/btrfs/bio.c:938\n  ------------[ cut here ]------------\n  assertion failed: !(fs_info-\u003esb-\u003es_flags \u0026 SB_RDONLY) :: 0, in fs/btrfs/bio.c:938\n  kernel BUG at fs/btrfs/bio.c:938!\n  Oops: invalid opcode: 0000 [#1] SMP NOPTI\n  CPU: 0 UID: 0 PID: 868 Comm: kworker/u8:13 Tainted: G        W        N  6.19.0-rc6+ #4788 PREEMPT(full)\n  Tainted: [W]=WARN, [N]=TEST\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\n  Workqueue: btrfs-endio simple_end_io_work\n  RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120\n  RSP: 0000:ffffc90001d2bcf0 EFLAGS: 00010246\n  RAX: 0000000000000051 RBX: 0000000000001000 RCX: 0000000000000000\n  RDX: 0000000000000000 RSI: ffffffff8305cf42 RDI: 00000000ffffffff\n  RBP: 0000000000000002 R08: 00000000fffeffff R09: ffffffff837fa988\n  R10: ffffffff8327a9e0 R11: 6f69747265737361 R12: ffff88813018d310\n  R13: ffff888168b8a000 R14: ffffc90001d2bd90 R15: ffff88810a169000\n  FS:  0000000000000000(0000) GS:ffff8885e752c000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  ------------[ cut here ]------------\n\n[CAUSE]\nThe cause of -ENOSPC error during the test case btrfs/124 is still\nunknown, although it's known that we still have cases where metadata can\nbe over-committed but can not be fulfilled correctly, thus if we hit\nsuch ENOSPC error inside a critical path, we have no choice but abort\nthe current transaction.\n\nThis will mark the fs read-only.\n\nThe problem is inside the btrfs_repair_io_failure() path that we require\nthe fs not to be mount read-only. This is normally fine, but if we are\ndoing a read-repair meanwhile the fs flips RO due to a critical error,\nwe can enter btrfs_repair_io_failure() with super block set to\nread-only, thus triggering the above crash.\n\n[FIX]\nJust replace the ASSERT() with a proper return if the fs is already\nread-only.",
  "id": "CVE-2026-43299",
  "modified": "2026-07-08T05:39:00.552440135Z",
  "published": "2026-05-08T13:11:20.872Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8ceaad6cd6e7fa5f73b0b2796a2e85d75d37e9f3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f6df18c001e3dcebc08482d0adeacd0cfea08593"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43299.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43299"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "btrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure()"
}