5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas commit 037770686126155eafc44501312989e2837b9659 upstream. The on-media namespace index field nslot is a u32 read from the DIMM label storage area. __nd_label_validate() bounds it against the config area size, but sizeof_namespace_label() returns unsigned, so the product nslot * label_size is evaluated in 32-bit and wraps modulo 2^32 before the comparison. A crafted nslot passes the bound and is then used as the loop trip count in nd_label_data_init(), whose memset() walks off the end of the config_size buffer: an out-of-bounds write. The field is not trusted -- it comes from the medium, or from userspace via ND_CMD_SET_CONFIG_DATA. Evaluate the product in 64-bit so the bound check is exact; conforming labels are unaffected. The check was safe when introduced by commit 4a826c83db4e ("libnvdimm: namespace indices: read and validate"): it multiplied by sizeof(struct nd_namespace_label), a size_t, so on a 64-bit build the product did not wrap. Commit 564e871aa66f ("libnvdimm, label: add v1.2 nvdimm label definitions") narrowed it to 32 bits when the label size became a runtime value read via sizeof_namespace_label(). Fixes: 564e871aa66f ("libnvdimm, label: add v1.2 nvdimm label definitions") Cc: stable@vger.kernel.org Reviewed-by: Alison Schofield Signed-off-by: Bryam Vargas Link: https://patch.msgid.link/20260624-b4-disp-d8279485-v3-1-cdb6cab28b41@proton.me Signed-off-by: Alison Schofield Signed-off-by: Greg Kroah-Hartman --- drivers/nvdimm/label.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/nvdimm/label.c +++ b/drivers/nvdimm/label.c @@ -194,7 +194,7 @@ static int __nd_label_validate(struct nv } nslot = __le32_to_cpu(nsindex[i]->nslot); - if (nslot * sizeof_namespace_label(ndd) + if ((u64)nslot * sizeof_namespace_label(ndd) + 2 * sizeof_namespace_index(ndd) > ndd->nsarea.config_size) { dev_dbg(dev, "nsindex%d nslot: %u invalid, config_size: %#x\n",