Description
In the Linux kernel, the following vulnerability has been resolved:
dm-verity: fix buffer overflow in FEC calculation
There's a buffer overflow in dm-verity-fec:
if (neras && *neras <= v->fec->roots) fio->erasures[(*neras)++] = i;
This allows *neras to reach roots + 1 (the post-increment pushes it past roots). This value is then passed as no_eras to decode_rs8(). Inside the RS decoder (lib/reed_solomon/decode_rs.c:113-121), the erasure locator polynomial loop writes lambda[j] where j can reach nroots + 1 — one element past the end of lambda[] (which is sized nroots + 1, valid indices 0..nroots). The out-of-bounds write lands on syn[0], corrupting the syndrome buffer.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWeakness enumeration
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
No affected versions have been published.
Timeline
- Published
- Aug 15, 2026
- Last modified
- Oct 21, 2026
- NVD status
- Received