{"cve":"CVE-2025-38626","nvd":{"published":"2025-08-22T16:15:36.193","modified":"2026-06-17T09:17:14.617","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to trigger foreground gc during f2fs_map_blocks() in lfs mode\n\nw/ \"mode=lfs\" mount option, generic/299 will cause system panic as below:\n\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/segment.c:2835!\nCall Trace:\n <TASK>\n f2fs_allocate_data_block+0x6f4/0xc50\n f2fs_map_blocks+0x970/0x1550\n f2fs_iomap_begin+0xb2/0x1e0\n iomap_iter+0x1d6/0x430\n __iomap_dio_rw+0x208/0x9a0\n f2fs_file_write_iter+0x6b3/0xfa0\n aio_write+0x15d/0x2e0\n io_submit_one+0x55e/0xab0\n __x64_sys_io_submit+0xa5/0x230\n do_syscall_64+0x84/0x2f0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\nRIP: 0010:new_curseg+0x70f/0x720\n\nThe root cause of we run out-of-space is: in f2fs_map_blocks(), f2fs may\ntrigger foreground gc only if it allocates any physical block, it will be\na little bit later when there is multiple threads writing data w/\naio/dio/bufio method in parallel, since we always use OPU in lfs mode, so\nf2fs_map_blocks() does block allocations aggressively.\n\nIn order to fix this issue, let's give a chance to trigger foreground\ngc in prior to block allocation in f2fs_map_blocks().","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/1005a3ca28e90c7a64fa43023f866b960a60f791","https://git.kernel.org/stable/c/264ede8a52f18647ed5bb5f2bd9bf54f556ad8f5","https://git.kernel.org/stable/c/385e64a0744584397b4b52b27c96703516f39968","https://git.kernel.org/stable/c/82765ce5c7a56f9309ee45328e763610eaf11253","https://git.kernel.org/stable/c/c737047f4665232d1e26b3620bc62df334545451"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:07:46.309729541+00:00"},"epss":{"cve":"CVE-2025-38626","score":0.00168,"percentile":0.05998,"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."]}