From 3e750e8419ff2ad1a7eb46d6d7a2a2b88d2d7be4 Mon Sep 17 00:00:00 2001
From: Alexandre Paillier <alexandre.paillier@ledger.fr>
Date: Thu, 1 Dec 2022 14:22:23 +0100
Subject: [PATCH] Fix device crash caused by improper memory alignment of the
 plugin context buffer

---
 src/shared_context.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/shared_context.h b/src/shared_context.h
index 54c7566..414586c 100644
--- a/src/shared_context.h
+++ b/src/shared_context.h
@@ -65,7 +65,9 @@ typedef struct tokenContext_t {
             uint8_t contractAddress[ADDRESS_LENGTH];
             uint8_t methodSelector[SELECTOR_LENGTH];
         };
-        uint8_t pluginContext[5 * INT256_LENGTH];
+        // This needs to be strictly 4 bytes aligned since pointers to it will be casted as
+        // plugin context struct pointers (structs that contain up to 4 bytes wide elements)
+        uint8_t pluginContext[5 * INT256_LENGTH] __attribute__((aligned(4)));
     };
 
 #ifdef HAVE_STARKWARE
@@ -77,6 +79,8 @@ typedef struct tokenContext_t {
 
 } tokenContext_t;
 
+_Static_assert((offsetof(tokenContext_t, pluginContext) % 4) == 0, "Plugin context not aligned");
+
 typedef struct publicKeyContext_t {
     cx_ecfp_public_key_t publicKey;
     char address[41];