GHSA-W7P5-2W2W-6HJM

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-08-13 15:34
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

btrfs: tracepoints: fix sleep while in atomic context in btrfs_sync_file()

The trace event btrfs_sync_file() is called in an atomic context (all trace events are) and its call to dput(), which is needed due to the call to dget_parent(), can sleep, triggering a kernel splat.

This can be reproduced by enabling the trace event and running btrfs/056 from fstests for example. The splat shown in dmesg is the following:

[53.919] BUG: sleeping function called from invalid context at fs/dcache.c:970 [53.947] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 32773, name: xfs_io [53.988] preempt_count: 2, expected: 0 [53.967] RCU nest depth: 0, expected: 0 [53.943] Preemption disabled at: [53.944] [<0000000000000000>] 0x0 [54.078] CPU: 0 UID: 0 PID: 32773 Comm: xfs_io Tainted: G W 7.1.0-rc1-btrfs-next-232+ #1 PREEMPT(full) [54.070] Tainted: [W]=WARN [54.071] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 [54.072] Call Trace: [54.074] [54.076] dump_stack_lvl+0x56/0x80 [54.079] __might_resched.cold+0xd6/0x10f [54.072] dput.part.0+0x24/0x110 [54.078] trace_event_raw_event_btrfs_sync_file+0x75/0x140 [btrfs] [54.089] btrfs_sync_file+0x1ed/0x530 [btrfs] [54.087] ? __handle_mm_fault+0x8ae/0xed0 [54.089] btrfs_do_write_iter+0x172/0x210 [btrfs] [54.091] vfs_write+0x21f/0x450 [54.094] __x64_sys_pwrite64+0x8d/0xc0 [54.096] ? do_user_addr_fault+0x20c/0x670 [54.099] do_syscall_64+0x60/0xf20 [54.092] ? clear_bhb_loop+0x60/0xb0 [54.094] entry_SYSCALL_64_after_hwframe+0x76/0x7e

So stop using dget_parent() and dput() and access the parent dentry directly as dentry->d_parent. This is also what ext4 is doing in its equivalent trace event ext4_sync_file_enter().

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-64164"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:58Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: tracepoints: fix sleep while in atomic context in btrfs_sync_file()\n\nThe trace event btrfs_sync_file() is called in an atomic context (all trace\nevents are) and its call to dput(), which is needed due to the call to\ndget_parent(), can sleep, triggering a kernel splat.\n\nThis can be reproduced by enabling the trace event and running btrfs/056\nfrom fstests for example. The splat shown in dmesg is the following:\n\n  [53.919] BUG: sleeping function called from invalid context at fs/dcache.c:970\n  [53.947] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 32773, name: xfs_io\n  [53.988] preempt_count: 2, expected: 0\n  [53.967] RCU nest depth: 0, expected: 0\n  [53.943] Preemption disabled at:\n  [53.944] [\u003c0000000000000000\u003e] 0x0\n  [54.078] CPU: 0 UID: 0 PID: 32773 Comm: xfs_io Tainted: G        W           7.1.0-rc1-btrfs-next-232+ #1 PREEMPT(full)\n  [54.070] Tainted: [W]=WARN\n  [54.071] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014\n  [54.072] Call Trace:\n  [54.074]  \u003cTASK\u003e\n  [54.076]  dump_stack_lvl+0x56/0x80\n  [54.079]  __might_resched.cold+0xd6/0x10f\n  [54.072]  dput.part.0+0x24/0x110\n  [54.078]  trace_event_raw_event_btrfs_sync_file+0x75/0x140 [btrfs]\n  [54.089]  btrfs_sync_file+0x1ed/0x530 [btrfs]\n  [54.087]  ? __handle_mm_fault+0x8ae/0xed0\n  [54.089]  btrfs_do_write_iter+0x172/0x210 [btrfs]\n  [54.091]  vfs_write+0x21f/0x450\n  [54.094]  __x64_sys_pwrite64+0x8d/0xc0\n  [54.096]  ? do_user_addr_fault+0x20c/0x670\n  [54.099]  do_syscall_64+0x60/0xf20\n  [54.092]  ? clear_bhb_loop+0x60/0xb0\n  [54.094]  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nSo stop using dget_parent() and dput() and access the parent dentry\ndirectly as dentry-\u003ed_parent. This is also what ext4 is doing in\nits equivalent trace event ext4_sync_file_enter().",
  "id": "GHSA-w7p5-2w2w-6hjm",
  "modified": "2026-08-13T15:34:15Z",
  "published": "2026-07-19T18:31:54Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64164"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0a96d9a85cd2240481297156b9bb72e10b7a8036"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/12a0487945c09760a5968d9333383014ea294117"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/26b2290baaf6da6add0f782a100766e686a33f4f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4361954f0e158af0530caa1e57f12b531be4658f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6279992c9ba2774901c9d4dd4a481162e2534714"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c32a7e0e3c73c1c0768556a56bd78de9f7b83780"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c73370c677646e86fc4b1780fb07027bdf847375"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d78b0a80eac36879ef5478707135c446920e134b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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