{"api_version":"1","generated_at":"2026-10-24T04:38:59+00:00","cve":"CVE-2025-40138","urls":{"html":"https://cve.report/CVE-2025-40138","api":"https://cve.report/api/cve/CVE-2025-40138.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-40138","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-40138"},"summary":{"title":"f2fs: fix to avoid NULL pointer dereference in f2fs_check_quota_consistency()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid NULL pointer dereference in f2fs_check_quota_consistency()\n\nsyzbot reported a f2fs bug as below:\n\nOops: gen[  107.736417][ T5848] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nCPU: 1 UID: 0 PID: 5848 Comm: syz-executor263 Tainted: G        W           6.17.0-rc1-syzkaller-00014-g0e39a731820a #0 PREEMPT_{RT,(full)}\nRIP: 0010:strcmp+0x3c/0xc0 lib/string.c:284\nCall Trace:\n <TASK>\n f2fs_check_quota_consistency fs/f2fs/super.c:1188 [inline]\n f2fs_check_opt_consistency+0x1378/0x2c10 fs/f2fs/super.c:1436\n __f2fs_remount fs/f2fs/super.c:2653 [inline]\n f2fs_reconfigure+0x482/0x1770 fs/f2fs/super.c:5297\n reconfigure_super+0x224/0x890 fs/super.c:1077\n do_remount fs/namespace.c:3314 [inline]\n path_mount+0xd18/0xfe0 fs/namespace.c:4112\n do_mount fs/namespace.c:4133 [inline]\n __do_sys_mount fs/namespace.c:4344 [inline]\n __se_sys_mount+0x317/0x410 fs/namespace.c:4321\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe direct reason is f2fs_check_quota_consistency() may suffer null-ptr-deref\nissue in strcmp().\n\nThe bug can be reproduced w/ below scripts:\nmkfs.f2fs -f /dev/vdb\nmount -t f2fs -o usrquota /dev/vdb /mnt/f2fs\nquotacheck -uc /mnt/f2fs/\numount /mnt/f2fs\nmount -t f2fs -o usrjquota=aquota.user,jqfmt=vfsold /dev/vdb /mnt/f2fs\nmount -t f2fs -o remount,usrjquota=,jqfmt=vfsold /dev/vdb /mnt/f2fs\numount /mnt/f2fs\n\nSo, before old_qname and new_qname comparison, we need to check whether\nthey are all valid pointers, fix it.","state":"PUBLISHED","assigner":"Linux","published_at":"2025-11-12 11:15:43","updated_at":"2026-10-19 21:10:00"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/3f3458852bbfe79c60f2412b8b04677b96688b6e","name":"https://git.kernel.org/stable/c/3f3458852bbfe79c60f2412b8b04677b96688b6e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/930a9a6ee8e7ffa20af4bffbfc2bbd21d83bf81c","name":"https://git.kernel.org/stable/c/930a9a6ee8e7ffa20af4bffbfc2bbd21d83bf81c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-40138","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-40138","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d185351325237da688de006a2c579e82ea97bdfe 3f3458852bbfe79c60f2412b8b04677b96688b6e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d185351325237da688de006a2c579e82ea97bdfe 930a9a6ee8e7ffa20af4bffbfc2bbd21d83bf81c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.17","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.17 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.17.3 6.17.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2025","cve_id":"40138","cve":"CVE-2025-40138","epss":"0.001980000","percentile":"0.090220000","score_date":"2026-10-19","updated_at":"2026-10-20 00:13:48"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/f2fs/super.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"3f3458852bbfe79c60f2412b8b04677b96688b6e","status":"affected","version":"d185351325237da688de006a2c579e82ea97bdfe","versionType":"git"},{"lessThan":"930a9a6ee8e7ffa20af4bffbfc2bbd21d83bf81c","status":"affected","version":"d185351325237da688de006a2c579e82ea97bdfe","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/f2fs/super.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.17"},{"lessThan":"6.17","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.17.*","status":"unaffected","version":"6.17.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.18","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.17.3","versionStartIncluding":"6.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18","versionStartIncluding":"6.17","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid NULL pointer dereference in f2fs_check_quota_consistency()\n\nsyzbot reported a f2fs bug as below:\n\nOops: gen[  107.736417][ T5848] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nCPU: 1 UID: 0 PID: 5848 Comm: syz-executor263 Tainted: G        W           6.17.0-rc1-syzkaller-00014-g0e39a731820a #0 PREEMPT_{RT,(full)}\nRIP: 0010:strcmp+0x3c/0xc0 lib/string.c:284\nCall Trace:\n <TASK>\n f2fs_check_quota_consistency fs/f2fs/super.c:1188 [inline]\n f2fs_check_opt_consistency+0x1378/0x2c10 fs/f2fs/super.c:1436\n __f2fs_remount fs/f2fs/super.c:2653 [inline]\n f2fs_reconfigure+0x482/0x1770 fs/f2fs/super.c:5297\n reconfigure_super+0x224/0x890 fs/super.c:1077\n do_remount fs/namespace.c:3314 [inline]\n path_mount+0xd18/0xfe0 fs/namespace.c:4112\n do_mount fs/namespace.c:4133 [inline]\n __do_sys_mount fs/namespace.c:4344 [inline]\n __se_sys_mount+0x317/0x410 fs/namespace.c:4321\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe direct reason is f2fs_check_quota_consistency() may suffer null-ptr-deref\nissue in strcmp().\n\nThe bug can be reproduced w/ below scripts:\nmkfs.f2fs -f /dev/vdb\nmount -t f2fs -o usrquota /dev/vdb /mnt/f2fs\nquotacheck -uc /mnt/f2fs/\numount /mnt/f2fs\nmount -t f2fs -o usrjquota=aquota.user,jqfmt=vfsold /dev/vdb /mnt/f2fs\nmount -t f2fs -o remount,usrjquota=,jqfmt=vfsold /dev/vdb /mnt/f2fs\numount /mnt/f2fs\n\nSo, before old_qname and new_qname comparison, we need to check whether\nthey are all valid pointers, fix it."}],"providerMetadata":{"dateUpdated":"2026-05-11T21:43:29.612Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/3f3458852bbfe79c60f2412b8b04677b96688b6e"},{"url":"https://git.kernel.org/stable/c/930a9a6ee8e7ffa20af4bffbfc2bbd21d83bf81c"}],"title":"f2fs: fix to avoid NULL pointer dereference in f2fs_check_quota_consistency()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2025-40138","datePublished":"2025-11-12T10:23:23.912Z","dateReserved":"2025-04-16T07:20:57.171Z","dateUpdated":"2026-05-11T21:43:29.612Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2025-11-12 11:15:43","lastModifiedDate":"2026-10-19 21:10:00","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2025","CveId":"40138","Ordinal":"1","Title":"f2fs: fix to avoid NULL pointer dereference in f2fs_check_quota_","CVE":"CVE-2025-40138","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"40138","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid NULL pointer dereference in f2fs_check_quota_consistency()\n\nsyzbot reported a f2fs bug as below:\n\nOops: gen[  107.736417][ T5848] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nCPU: 1 UID: 0 PID: 5848 Comm: syz-executor263 Tainted: G        W           6.17.0-rc1-syzkaller-00014-g0e39a731820a #0 PREEMPT_{RT,(full)}\nRIP: 0010:strcmp+0x3c/0xc0 lib/string.c:284\nCall Trace:\n <TASK>\n f2fs_check_quota_consistency fs/f2fs/super.c:1188 [inline]\n f2fs_check_opt_consistency+0x1378/0x2c10 fs/f2fs/super.c:1436\n __f2fs_remount fs/f2fs/super.c:2653 [inline]\n f2fs_reconfigure+0x482/0x1770 fs/f2fs/super.c:5297\n reconfigure_super+0x224/0x890 fs/super.c:1077\n do_remount fs/namespace.c:3314 [inline]\n path_mount+0xd18/0xfe0 fs/namespace.c:4112\n do_mount fs/namespace.c:4133 [inline]\n __do_sys_mount fs/namespace.c:4344 [inline]\n __se_sys_mount+0x317/0x410 fs/namespace.c:4321\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe direct reason is f2fs_check_quota_consistency() may suffer null-ptr-deref\nissue in strcmp().\n\nThe bug can be reproduced w/ below scripts:\nmkfs.f2fs -f /dev/vdb\nmount -t f2fs -o usrquota /dev/vdb /mnt/f2fs\nquotacheck -uc /mnt/f2fs/\numount /mnt/f2fs\nmount -t f2fs -o usrjquota=aquota.user,jqfmt=vfsold /dev/vdb /mnt/f2fs\nmount -t f2fs -o remount,usrjquota=,jqfmt=vfsold /dev/vdb /mnt/f2fs\numount /mnt/f2fs\n\nSo, before old_qname and new_qname comparison, we need to check whether\nthey are all valid pointers, fix it.","Type":"Description","Title":"f2fs: fix to avoid NULL pointer dereference in f2fs_check_quota_"}]}}}