From 27333f9ce84badbf4b97b08be8c8f9a98b10b791 Mon Sep 17 00:00:00 2001
From: Fabian Freyer <fabian.freyer@physik.tu-berlin.de>
Date: Mon, 18 Sep 2023 23:17:54 +0200
Subject: [PATCH] libafl_bolts fix potentially unaligned ucontexts in signal
 handler (#1520)

When entering a signal handler, the ucontext_t is not necessarily 0x10-aligned, so we need to use read_unaligned instead of dereferencing.
---
 libafl_bolts/src/os/unix_signals.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libafl_bolts/src/os/unix_signals.rs b/libafl_bolts/src/os/unix_signals.rs
index 6f4eb87d48..ffae70b019 100644
--- a/libafl_bolts/src/os/unix_signals.rs
+++ b/libafl_bolts/src/os/unix_signals.rs
@@ -390,7 +390,11 @@ unsafe fn handle_signal(sig: c_int, info: siginfo_t, void: *mut c_void) {
             None => return,
         }
     };
-    handler.handle(*signal, info, &mut *(void as *mut ucontext_t));
+    handler.handle(
+        *signal,
+        info,
+        &mut ptr::read_unaligned(void as *mut ucontext_t),
+    );
 }
 
 /// Setup signal handlers in a somewhat rusty way.