The size of messages' payload is miscalculated, leading to extra data passed to the message handler. While this is not a problem with our current set of commands, others with a variable-length payload may misbehave. Fix this.
Signed-off-by: Alexandre Courbot <[email protected]> --- drivers/gpu/nova-core/gsp/cmdq.rs | 11 +++++++---- drivers/gpu/nova-core/gsp/fw.rs | 2 +- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs index 6f946d14868a..dab73377c526 100644 --- a/drivers/gpu/nova-core/gsp/cmdq.rs +++ b/drivers/gpu/nova-core/gsp/cmdq.rs @@ -588,21 +588,24 @@ fn wait_for_msg(&self, timeout: Delta) -> Result<GspMessage<'_>> { header.length(), ); + // The length of the message that follows the header. + let msg_length = header.length() - size_of::<GspMsgElement>(); + // Check that the driver read area is large enough for the message. - if slice_1.len() + slice_2.len() < header.length() { + if slice_1.len() + slice_2.len() < msg_length { return Err(EIO); } // Cut the message slices down to the actual length of the message. - let (slice_1, slice_2) = if slice_1.len() > header.length() { + let (slice_1, slice_2) = if slice_1.len() > msg_length { // PANIC: we checked above that `slice_1` is at least as long as `msg_header.length()`. - (slice_1.split_at(header.length()).0, &slice_2[0..0]) + (slice_1.split_at(msg_length).0, &slice_2[0..0]) } else { ( slice_1, // PANIC: we checked above that `slice_1.len() + slice_2.len()` is at least as // large as `msg_header.length()`. - slice_2.split_at(header.length() - slice_1.len()).0, + slice_2.split_at(msg_length - slice_1.len()).0, ) }; diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs index abffd6beec65..7fcba5afb0a3 100644 --- a/drivers/gpu/nova-core/gsp/fw.rs +++ b/drivers/gpu/nova-core/gsp/fw.rs @@ -853,7 +853,7 @@ pub(crate) fn set_checksum(&mut self, checksum: u32) { self.inner.checkSum = checksum; } - /// Returns the total length of the message. + /// Returns the total length of the message, message and RPC headers included. pub(crate) fn length(&self) -> usize { // `rpc.length` includes the length of the GspRpcHeader but not the message header. size_of::<Self>() - size_of::<bindings::rpc_message_header_v>() -- 2.51.2
