5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bryam Vargas <redacted>
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: <redacted>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Bryam Vargas <redacted>
Link: https://patch.msgid.link/20260624-b4-disp-d8279485-v3-1-cdb6cab28b41@proton.me (local)
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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",