{"cve":"CVE-2026-31434","nvd":{"published":"2026-04-22T14:16:36.533","modified":"2026-06-17T10:33:42.890","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix leak of kobject name for sub-group space_info\n\nWhen create_space_info_sub_group() allocates elements of\nspace_info->sub_group[], kobject_init_and_add() is called for each\nelement via btrfs_sysfs_add_space_info_type(). However, when\ncheck_removing_space_info() frees these elements, it does not call\nbtrfs_sysfs_remove_space_info() on them. As a result, kobject_put() is\nnot called and the associated kobj->name objects are leaked.\n\nThis memory leak is reproduced by running the blktests test case\nzbd/009 on kernels built with CONFIG_DEBUG_KMEMLEAK. The kmemleak\nfeature reports the following error:\n\nunreferenced object 0xffff888112877d40 (size 16):\n  comm \"mount\", pid 1244, jiffies 4294996972\n  hex dump (first 16 bytes):\n    64 61 74 61 2d 72 65 6c 6f 63 00 c4 c6 a7 cb 7f  data-reloc......\n  backtrace (crc 53ffde4d):\n    __kmalloc_node_track_caller_noprof+0x619/0x870\n    kstrdup+0x42/0xc0\n    kobject_set_name_vargs+0x44/0x110\n    kobject_init_and_add+0xcf/0x150\n    btrfs_sysfs_add_space_info_type+0xfc/0x210 [btrfs]\n    create_space_info_sub_group.constprop.0+0xfb/0x1b0 [btrfs]\n    create_space_info+0x211/0x320 [btrfs]\n    btrfs_init_space_info+0x15a/0x1b0 [btrfs]\n    open_ctree+0x33c7/0x4a50 [btrfs]\n    btrfs_get_tree.cold+0x9f/0x1ee [btrfs]\n    vfs_get_tree+0x87/0x2f0\n    vfs_cmd_create+0xbd/0x280\n    __do_sys_fsconfig+0x3df/0x990\n    do_syscall_64+0x136/0x1540\n    entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nTo avoid the leak, call btrfs_sysfs_remove_space_info() instead of\nkfree() for the elements.","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":["CWE-401"],"references":["https://git.kernel.org/stable/c/1737ddeafbb1304f41ec2eede4f7366082e7c96a","https://git.kernel.org/stable/c/3c645c6f7e5470debbb81666b230056de48f36dc","https://git.kernel.org/stable/c/3c844d01f9874a43004c82970d8da94f9aba8949","https://git.kernel.org/stable/c/416484f21a9d1280cf6daa7ebc10c79b59c46e48","https://git.kernel.org/stable/c/94054ffd311a1f76b7093ba8ebf50bdb0d28337c"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:30:49.762551342+00:00"},"epss":{"cve":"CVE-2026-31434","score":0.00123,"percentile":0.02,"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."]}