From 9c0791d20aa8d3507fa55a28ff890c1ebcbae649 Mon Sep 17 00:00:00 2001
From: Jan Niehusmann <jan@gondor.com>
Date: Tue, 21 Oct 2025 19:58:18 +0000
Subject: [PATCH 1/4] Implement SpiOperation::TransferInPlace based on
 SpidevTransfer::read_write_in_place()

Fixes #120
---
 Cargo.toml | 2 +-
 src/spi.rs | 9 ++-------
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 6371f30..4e98066 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -31,7 +31,7 @@ sysfs_gpio = { version = "0.6.1", optional = true }
 i2cdev = { version = "0.6.0", optional = true }
 nb = "1"
 serialport = { version = "4.2.0", default-features = false, optional = true }
-spidev = { version = "0.6.0", optional = true }
+spidev = { version = "0.7.0", optional = true, git = "https://github.com/rust-embedded/rust-spidev.git", rev = "refs/pull/49/head" }
 nix = { version = "0.27.1", optional = true }
 tokio = { version = "1", default-features = false, optional = true }
 
diff --git a/src/spi.rs b/src/spi.rs
index 675506e..9854dde 100644
--- a/src/spi.rs
+++ b/src/spi.rs
@@ -173,9 +173,8 @@ mod embedded_hal_impl {
         }
 
         fn transfer_in_place(&mut self, words: &mut [u8]) -> Result<(), Self::Error> {
-            let tx = words.to_owned();
             self.0
-                .transfer(&mut SpidevTransfer::read_write(&tx, words))
+                .transfer(&mut SpidevTransfer::read_write_in_place(words))
                 .map_err(|err| SPIError { err })
         }
 
@@ -214,11 +213,7 @@ mod embedded_hal_impl {
                         }
                     },
                     SpiOperation::TransferInPlace(buf) => {
-                        let tx = unsafe {
-                            let p = buf.as_ptr();
-                            std::slice::from_raw_parts(p, buf.len())
-                        };
-                        transfers.push(SpidevTransfer::read_write(tx, buf));
+                        transfers.push(SpidevTransfer::read_write_in_place(buf));
                     }
                     SpiOperation::DelayNs(ns) => {
                         let us = {

From 68d7e8ce2e3789f158c55126d14995af3d723024 Mon Sep 17 00:00:00 2001
From: Jan Niehusmann <jan@gondor.com>
Date: Thu, 23 Oct 2025 22:09:27 +0000
Subject: [PATCH 2/4] Use spidev 0.6.1 instead of 0.7.0 to avoid breaking
 change

---
 Cargo.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index 4e98066..894de2f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -31,7 +31,7 @@ sysfs_gpio = { version = "0.6.1", optional = true }
 i2cdev = { version = "0.6.0", optional = true }
 nb = "1"
 serialport = { version = "4.2.0", default-features = false, optional = true }
-spidev = { version = "0.7.0", optional = true, git = "https://github.com/rust-embedded/rust-spidev.git", rev = "refs/pull/49/head" }
+spidev = { version = "0.6.1", optional = true }
 nix = { version = "0.27.1", optional = true }
 tokio = { version = "1", default-features = false, optional = true }
 

From 1c061ff0683f2cb3ed947586feebfa49e81f7400 Mon Sep 17 00:00:00 2001
From: Jan Niehusmann <jan@gondor.com>
Date: Thu, 23 Oct 2025 22:15:07 +0000
Subject: [PATCH 3/4] Add changelog entry

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dbcc339..2f51f00 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Added async `DelayNs` implementation for `tokio`.
 - Added feature flag for `serial`.
 
+### Fixed
+
+- Fix UB (and remove unsafe block) in handling of SpiOperation::TransferInPlace
+
 ## [v0.4.0] - 2024-01-10
 
 ### Changed

From 88abb3cebac5ede511af98432512c367cccb9a14 Mon Sep 17 00:00:00 2001
From: Jan Niehusmann <jan@gondor.com>
Date: Thu, 23 Oct 2025 22:32:28 +0000
Subject: [PATCH 4/4] Fix CI on MSRV

---
 .github/workflows/ci.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a84a4e0..945ada9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -37,6 +37,9 @@ jobs:
           toolchain: ${{ matrix.rust }}
           target: ${{ matrix.target }}
 
+      - if: ${{ matrix.rust=='1.65.0' }}
+        run: cargo update --precise 2.0.106 --package syn
+
       - name: Install armv7 libraries
         if: ${{ matrix.target == 'armv7-unknown-linux-gnueabihf' }}
         run: |