Re: [PATCH v1 2/5] gpu: nova-core: use checked arithmetic in Booter signature parsing
From: Joel Fernandes
Date: Mon Jan 26 2026 - 06:02:43 EST
On 1/26/2026 3:08 AM, Zhi Wang wrote:
On Sat, 24 Jan 2026 18:18:27 -0500Fixed and applied your tags, thank you!
Joel Fernandes <joelagnelf@xxxxxxxxxx> wrote:
Use checked_add() when computing signature offsets from firmware-
provided values in signatures_iter().
Without checked arithmetic, overflow could wrap to a small plausible
offset that points to entirely wrong data.
Signed-off-by: Joel Fernandes <joelagnelf@xxxxxxxxxx>
---
drivers/gpu/nova-core/firmware/booter.rs | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/nova-core/firmware/booter.rs
b/drivers/gpu/nova-core/firmware/booter.rs index
86556cee8e67..f5ad619dc055 100644 ---
a/drivers/gpu/nova-core/firmware/booter.rs +++
b/drivers/gpu/nova-core/firmware/booter.rs @@ -119,14 +119,23 @@ fn
signatures_iter(&'a self) -> Result<impl Iterator<Item =
BooterSignature<'a>> Some(sig_size) => { let patch_sig =
frombytes_at::<u32>(self.fw,
self.hdr.patch_sig_offset.into_safe_cast())?;
- let signatures_start =
usize::from_safe_cast(self.hdr.sig_prod_offset + patch_sig); +
+ // Compute signatures_start = hdr.sig_prod_offset +
patch_sig.
+ let signatures_start = self
+ .hdr
+ .sig_prod_offset
+ .checked_add(patch_sig)
+ .map(usize::from_safe_cast)
+ .ok_or(EINVAL)?;
+
+ // Compute signatures_end = signatures_start +
hdr.sig_prod_size.
+ let signatures_end = signatures_start
+
.checked_add(usize::from_safe_cast(self.hdr.sig_prod_size))
+ .ok_or(EINVAL)?;
The same concern of comment format in PATCH 1 raised by Dirk, With that
addressed,
Reviewed-by: Zhi Wang <zhiw@xxxxxxxxxx>
--
Joel Fernandes