{"cve":"CVE-2026-64164","nvd":{"published":"2026-07-19T16:17:58.450","modified":"2026-08-13T15:33:00.410","status":"Analyzed","description":"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] [<0000000000000000>] 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]  <TASK>\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->d_parent. This is also what ext4 is doing in\nits equivalent trace event ext4_sync_file_enter().","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/0a96d9a85cd2240481297156b9bb72e10b7a8036","https://git.kernel.org/stable/c/12a0487945c09760a5968d9333383014ea294117","https://git.kernel.org/stable/c/26b2290baaf6da6add0f782a100766e686a33f4f","https://git.kernel.org/stable/c/4361954f0e158af0530caa1e57f12b531be4658f","https://git.kernel.org/stable/c/6279992c9ba2774901c9d4dd4a481162e2534714"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:45:36.895656543+00:00"},"epss":{"cve":"CVE-2026-64164","score":0.00114,"percentile":0.01476,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}