{"id":"CVE-2026-72197","summary":"fs/ntfs3: bound DeleteIndexEntryAllocation memmove length","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: bound DeleteIndexEntryAllocation memmove length\n\nIn do_action()'s DeleteIndexEntryAllocation case, e-\u003esize comes\nfrom an on-disk INDEX_BUFFER entry.  When e-\u003esize makes\ne + e-\u003esize point past hdr + hdr-\u003eused,\nPtrOffset(e1, Add2Ptr(hdr, used)) returns a negative ptrdiff_t\nthat is silently cast to a quasi-infinite size_t when passed\nto memmove().  The memmove then walks past the destination\nbuffer.\n\nThe sibling DeleteIndexEntryRoot case at fslog.c:3540-3543\nalready carries the corresponding guard:\n\n\tif (PtrOffset(e1, Add2Ptr(hdr, used)) \u003c esize ||\n\t    Add2Ptr(e, esize) \u003e Add2Ptr(lrh, rec_len) ||\n\t    used + esize \u003e le32_to_cpu(hdr-\u003etotal)) {\n\t\tgoto dirty_vol;\n\t}\n\nApply the same shape to the allocation-path case.  Also reject\nesize == 0: memmove(e, e, ...) is a no-op and leaves\nhdr-\u003eused unchanged, hiding a malformed entry from the\nexisting check_index_header() walk.\n\nReproduced under UML+KASAN on mainline 8d90b09e6741 by\nmounting a crafted NTFS image: the unguarded memmove takes a\nlength of 0xffffffffffffff00 and the kernel oopses in\nmemmove+0x81/0x1a0 on the do_action+0x36a2 frame.\n\n[almaz.alexandrovich@paragon-software.com: clang-formatted the changes]","modified":"2026-08-18T03:56:21.752778232Z","published":"2026-08-15T05:53:56.149Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72197.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/09fddd52c1b0cef2c086d61be8f3d5dc92e36565"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4c8aac931c1cd70347961ba5157aa916448c6a25"},{"type":"WEB","url":"https://git.kernel.org/stable/c/554700c65d398276cb00a8ef95f1d5e00b9eff93"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b509b9613f20dc5b653d54bf78fab00d79cc43c8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c38ed2ab62fab75fd6d0fdc2bee540fbebc7b959"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f383aae59ec3994c14804f4191c59038b206be81"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fc4626bb3656362de8b0ecd56605d47a19ec3518"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72197.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72197"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b46acd6a6a627d876898e1c84d3f84902264b445"},{"fixed":"c38ed2ab62fab75fd6d0fdc2bee540fbebc7b959"},{"fixed":"b509b9613f20dc5b653d54bf78fab00d79cc43c8"},{"fixed":"4c8aac931c1cd70347961ba5157aa916448c6a25"},{"fixed":"f383aae59ec3994c14804f4191c59038b206be81"},{"fixed":"09fddd52c1b0cef2c086d61be8f3d5dc92e36565"},{"fixed":"554700c65d398276cb00a8ef95f1d5e00b9eff93"},{"fixed":"fc4626bb3656362de8b0ecd56605d47a19ec3518"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72197.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72197.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}