{"cve":"CVE-2026-43408","nvd":{"published":"2026-05-08T15:16:52.397","modified":"2026-10-21T13:18:56.273","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: add a bunch of missing ceph_path_info initializers\n\nceph_mdsc_build_path() must be called with a zero-initialized\nceph_path_info parameter, or else the following\nceph_mdsc_free_path_info() may crash.\n\nExample crash (on Linux 6.18.12):\n\n  virt_to_cache: Object is not a Slab page!\n  WARNING: CPU: 184 PID: 2871736 at mm/slub.c:6732 kmem_cache_free+0x316/0x400\n  [...]\n  Call Trace:\n   [...]\n   ceph_open+0x13d/0x3e0\n   do_dentry_open+0x134/0x480\n   vfs_open+0x2a/0xe0\n   path_openat+0x9a3/0x1160\n  [...]\n  cache_from_obj: Wrong slab cache. names_cache but object is from ceph_inode_info\n  WARNING: CPU: 184 PID: 2871736 at mm/slub.c:6746 kmem_cache_free+0x2dd/0x400\n  [...]\n  kernel BUG at mm/slub.c:634!\n  Oops: invalid opcode: 0000 [#1] SMP NOPTI\n  RIP: 0010:__slab_free+0x1a4/0x350\n\nSome of the ceph_mdsc_build_path() callers had initializers, but\nothers had not, even though they were all added by commit 15f519e9f883\n(\"ceph: fix race condition validating r_parent before applying state\").\nThe ones without initializer are suspectible to random crashes.  (I can\nimagine it could even be possible to exploit this bug to elevate\nprivileges.)\n\nUnfortunately, these Ceph functions are undocumented and its semantics\ncan only be derived from the code.  I see that ceph_mdsc_build_path()\ninitializes the structure only on success, but not on error.\n\nCalling ceph_mdsc_free_path_info() after a failed\nceph_mdsc_build_path() call does not even make sense, but that's what\nall callers do, and for it to be safe, the structure must be\nzero-initialized.  The least intrusive approach to fix this is\ntherefore to add initializers everywhere.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-476","CWE-457"],"references":["https://git.kernel.org/stable/c/43323a5934b660afae687e8e4e95ac328615a5c4","https://git.kernel.org/stable/c/453df1f4535842bf17ff1885a225e153d7ee3374","https://git.kernel.org/stable/c/644b47f0574fd82aeb9d00317eca8d1f2a525c8c","https://git.kernel.org/stable/c/8be8911f590813e6f90bc6407ced1b23e50bc5da"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-43408","score":0.00163,"percentile":0.05479,"date":"2026-10-25"},"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."]}