{"cve":"CVE-2025-38218","nvd":{"published":"2025-07-04T14:15:30.353","modified":"2026-07-30T06:23:00.933","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to do sanity check on sit_bitmap_size\n\nw/ below testcase, resize will generate a corrupted image which\ncontains inconsistent metadata, so when mounting such image, it\nwill trigger kernel panic:\n\ntouch img\ntruncate -s $((512*1024*1024*1024)) img\nmkfs.f2fs -f img $((256*1024*1024))\nresize.f2fs -s -i img -t $((1024*1024*1024))\nmount img /mnt/f2fs\n\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/segment.h:863!\nOops: invalid opcode: 0000 [#1] SMP PTI\nCPU: 11 UID: 0 PID: 3922 Comm: mount Not tainted 6.15.0-rc1+ #191 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:f2fs_ra_meta_pages+0x47c/0x490\n\nCall Trace:\n f2fs_build_segment_manager+0x11c3/0x2600\n f2fs_fill_super+0xe97/0x2840\n mount_bdev+0xf4/0x140\n legacy_get_tree+0x2b/0x50\n vfs_get_tree+0x29/0xd0\n path_mount+0x487/0xaf0\n __x64_sys_mount+0x116/0x150\n do_syscall_64+0x82/0x190\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\nRIP: 0033:0x7fdbfde1bcfe\n\nThe reaseon is:\n\nsit_i->bitmap_size is 192, so size of sit bitmap is 192*8=1536, at maximum\nthere are 1536 sit blocks, however MAIN_SEGS is 261893, so that sit_blk_cnt\nis 4762, build_sit_entries() -> current_sit_addr() tries to access\nout-of-boundary in sit_bitmap at offset from [1536, 4762), once sit_bitmap\nand sit_bitmap_mirror is not the same, it will trigger f2fs_bug_on().\n\nLet's add sanity check in f2fs_sanity_check_ckpt() to avoid panic.","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/38ef48a8afef8df646b6f6ae7abb872f18b533c1","https://git.kernel.org/stable/c/3e5ac62a56a24f4d88ce8ffd7bc452428b235868","https://git.kernel.org/stable/c/5db0d252c64e91ba1929c70112352e85dc5751e7","https://git.kernel.org/stable/c/79ef8a6c4ec53d327580fd7d2b522cf4f1d05b0c","https://git.kernel.org/stable/c/82f51bff393e4c12cf4de553120ca831cfa4ef19"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:04:28.436527499+00:00"},"epss":{"cve":"CVE-2025-38218","score":0.00187,"percentile":0.08353,"date":"2026-10-31"},"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."]}