{"cve":"CVE-2025-38063","nvd":{"published":"2025-06-18T10:15:39.207","modified":"2026-06-17T09:15:58.837","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm: fix unconditional IO throttle caused by REQ_PREFLUSH\n\nWhen a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush()\ngenerates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,\nwhich causes the flush_bio to be throttled by wbt_wait().\n\nAn example from v5.4, similar problem also exists in upstream:\n\n    crash> bt 2091206\n    PID: 2091206  TASK: ffff2050df92a300  CPU: 109  COMMAND: \"kworker/u260:0\"\n     #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8\n     #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4\n     #2 [ffff800084a2f880] schedule at ffff800040bfa4b4\n     #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4\n     #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc\n     #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0\n     #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254\n     #7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38\n     #8 [ffff800084a2fa60] generic_make_request at ffff800040570138\n     #9 [ffff800084a2fae0] submit_bio at ffff8000405703b4\n    #10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs]\n    #11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs]\n    #12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs]\n    #13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs]\n    #14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs]\n    #15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs]\n    #16 [ffff800084a2fdb0] process_one_work at ffff800040111d08\n    #17 [ffff800084a2fe00] worker_thread at ffff8000401121cc\n    #18 [ffff800084a2fe70] kthread at ffff800040118de4\n\nAfter commit 2def2845cc33 (\"xfs: don't allow log IO to be throttled\"),\nthe metadata submitted by xlog_write_iclog() should not be throttled.\nBut due to the existence of the dm layer, throttling flush_bio indirectly\ncauses the metadata bio to be throttled.\n\nFix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes\nwbt_should_throttle() return false to avoid wbt_wait().","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":[],"references":["https://git.kernel.org/stable/c/2858cda9a8d95e6deee7e3b0a26adde696a9a4f5","https://git.kernel.org/stable/c/52aa28f7b1708d76e315d78b5ed397932a1a97c3","https://git.kernel.org/stable/c/88f7f56d16f568f19e1a695af34a7f4a6ce537a6","https://git.kernel.org/stable/c/95d08924335f3b6f4ea0b92ebfe4fe0731c502d9","https://git.kernel.org/stable/c/b55a97d1bd4083729a60d19beffe85d4c96680de"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:03:23.287444849+00:00"},"epss":{"cve":"CVE-2025-38063","score":0.00182,"percentile":0.07801,"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."]}