[PATCH v3 04/11] gpu: nova-core: vbios: use checked access in `FwSecBiosImage::header`

Eliot Courtney
2026-04-21T08:21:00Z

Use checked access in `FwSecBiosImage::header` for getting the header
version since the value is firmware derived.

Fixes: 47c4846e4319 ("gpu: nova-core: vbios: Add support for FWSEC ucode extraction")
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/vbios.rs | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/nova-core/vbios.rs b/drivers/gpu/nova-core/vbios.rs
index 632c8a90ea76..bc752d135cbf 100644
--- a/drivers/gpu/nova-core/vbios.rs
+++ b/drivers/gpu/nova-core/vbios.rs
@@ -996,17 +996,14 @@ fn build(self) -> Result<FwSecBiosImage> {
impl FwSecBiosImage {
/// Get the FwSec header ([`FalconUCodeDesc`]).
pub(crate) fn header(&self) -> Result<FalconUCodeDesc> {
- // Get the falcon ucode offset that was found in setup_falcon_data.
- let falcon_ucode_offset = self.falcon_ucode_offset;
+ let data = self
+ .base
+ .data
+ .get(self.falcon_ucode_offset..)
+ .ok_or(EINVAL)?;

- // Read the first 4 bytes to get the version.
- let hdr_bytes: [u8; 4] = self.base.data[falcon_ucode_offset..falcon_ucode_offset + 4]
- .try_into()
- .map_err(|_| EINVAL)?;
- let hdr = u32::from_le_bytes(hdr_bytes);
- let ver = (hdr & 0xff00) >> 8;
-
- let data = self.base.data.get(falcon_ucode_offset..).ok_or(EINVAL)?;
+ // Read the version byte from the header.
+ let ver = data.get(1).copied().ok_or(EINVAL)?;
match ver {
2 => {
let v2 = FalconUCodeDescV2::from_bytes_copy_prefix(data)

--
2.53.0