{"cve":"CVE-2026-46130","nvd":{"published":"2026-05-28T10:16:28.570","modified":"2026-10-21T13:19:03.957","status":"Undergoing Analysis","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm-verity-fec: fix reading parity bytes split across blocks (take 3)\n\nfec_decode_bufs() assumes that the parity bytes of the first RS codeword\nit decodes are never split across parity blocks.\n\nThis assumption is false.  Consider v->fec->block_size == 4096 &&\nv->fec->roots == 17 && fio->nbufs == 1, for example.  In that case, each\ncall to fec_decode_bufs() consumes v->fec->roots * (fio->nbufs <<\nDM_VERITY_FEC_BUF_RS_BITS) = 272 parity bytes.\n\nConsidering that the parity data for each message block starts on a\nblock boundary, the byte alignment in the parity data will iterate\nthrough 272*i mod 4096 until the 3 parity blocks have been consumed.  On\nthe 16th call (i=15), the alignment will be 4080 bytes into the first\nblock.  Only 16 bytes remain in that block, but 17 parity bytes will be\nneeded.  The code reads out-of-bounds from the parity block buffer.\n\nFortunately this doesn't normally happen, since it can occur only for\ncertain non-default values of fec_roots *and* when the maximum number of\nbuffers couldn't be allocated due to low memory.  For example with\nblock_size=4096 only the following cases are affected:\n\n    fec_roots=17: nbufs in [1, 3, 5, 15]\n    fec_roots=19: nbufs in [1, 229]\n    fec_roots=21: nbufs in [1, 3, 5, 13, 15, 39, 65, 195]\n    fec_roots=23: nbufs in [1, 89]\n\nRegardless, fix it by refactoring how the parity blocks are read.","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:N/A:H","score":7.1},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/03348b440f69417dc3a3c71d8271cff6b05f67fb","https://git.kernel.org/stable/c/3d1b4e2d8ac0a1a1390a117f61ce0ca1c47e3bcb","https://git.kernel.org/stable/c/430a05cb926f6bdf53e81460a2c3a553257f3f61","https://git.kernel.org/stable/c/d47281b9a4472cfd73122393e79fbe76b651e46a","https://git.kernel.org/stable/c/dac69d1b76049d7e5f565089a6a7f4502a85b9de"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-46130","score":0.00126,"percentile":0.02242,"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."]}