FKIE_CVE-2026-43299

Vulnerability from fkie_nvd - Published: 2026-05-08 14:16 - Updated: 2026-05-15 14:13
Severity
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: btrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure() [BUG] There is a bug report that when btrfs hits ENOSPC error in a critical path, btrfs flips RO (this part is expected, although the ENOSPC bug still needs to be addressed). The problem is after the RO flip, if there is a read repair pending, we can hit the ASSERT() inside btrfs_repair_io_failure() like the following: BTRFS info (device vdc): relocating block group 30408704 flags metadata|raid1 ------------[ cut here ]------------ BTRFS: Transaction aborted (error -28) WARNING: fs/btrfs/extent-tree.c:3235 at __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844 Modules linked in: kvm_intel kvm irqbypass [...] ---[ end trace 0000000000000000 ]--- BTRFS info (device vdc state EA): 2 enospc errors during balance BTRFS info (device vdc state EA): balance: ended with status: -30 BTRFS error (device vdc state EA): parent transid verify failed on logical 30556160 mirror 2 wanted 8 found 6 BTRFS error (device vdc state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt 10, gen 0 [...] assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938 ------------[ cut here ]------------ assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938 kernel BUG at fs/btrfs/bio.c:938! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 868 Comm: kworker/u8:13 Tainted: G W N 6.19.0-rc6+ #4788 PREEMPT(full) Tainted: [W]=WARN, [N]=TEST Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 Workqueue: btrfs-endio simple_end_io_work RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120 RSP: 0000:ffffc90001d2bcf0 EFLAGS: 00010246 RAX: 0000000000000051 RBX: 0000000000001000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8305cf42 RDI: 00000000ffffffff RBP: 0000000000000002 R08: 00000000fffeffff R09: ffffffff837fa988 R10: ffffffff8327a9e0 R11: 6f69747265737361 R12: ffff88813018d310 R13: ffff888168b8a000 R14: ffffc90001d2bd90 R15: ffff88810a169000 FS: 0000000000000000(0000) GS:ffff8885e752c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 ------------[ cut here ]------------ [CAUSE] The cause of -ENOSPC error during the test case btrfs/124 is still unknown, although it's known that we still have cases where metadata can be over-committed but can not be fulfilled correctly, thus if we hit such ENOSPC error inside a critical path, we have no choice but abort the current transaction. This will mark the fs read-only. The problem is inside the btrfs_repair_io_failure() path that we require the fs not to be mount read-only. This is normally fine, but if we are doing a read-repair meanwhile the fs flips RO due to a critical error, we can enter btrfs_repair_io_failure() with super block set to read-only, thus triggering the above crash. [FIX] Just replace the ASSERT() with a proper return if the fs is already read-only.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8ceaad6cd6e7fa5f73b0b2796a2e85d75d37e9f3Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f6df18c001e3dcebc08482d0adeacd0cfea08593Patch
Impacted products
Vendor Product Version
linux linux_kernel *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "8E1EFD5F-CD3D-4FD8-8AB9-DBB8D001D8F3",
              "versionEndExcluding": "6.19.6",
              "versionStartIncluding": "3.13",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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\u0027s 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",
  "lastModified": "2026-05-15T14:13:43.660",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-05-08T14:16:37.100",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/8ceaad6cd6e7fa5f73b0b2796a2e85d75d37e9f3"
    },
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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