libnoaslr support for netbsd (#1366)

AFLplusplus · Jul 14, 2023 · eb362c5 · eb362c5
1 parent 11fc57a
commit eb362c5
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Showing 3 changed files with 102 additions and 9 deletions.
diff --git a/utils/noaslr/libnoaslr/Cargo.toml b/utils/noaslr/libnoaslr/Cargo.toml
@@ -15,5 +15,5 @@ anyhow = { version = "1.0.71", default-features = false }
 ctor = { version = "0.2.2", default-features = false }
 nix = { version = "0.26.2", default-features = false, features = ["process", "personality"] }
 
-[target.'cfg(target_os = "freebsd")'.dependencies]
+[target.'cfg(any(target_os = "freebsd", target_os = "netbsd"))'.dependencies]
 libc = "0.2" 
diff --git a/utils/noaslr/libnoaslr/src/lib.rs b/utils/noaslr/libnoaslr/src/lib.rs
@@ -1,8 +1,3 @@
-#[cfg(not(any(target_os = "linux", target_os = "android")))]
-use {
-    anyhow::{anyhow, Result},
-    ctor::ctor,
-};
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use {
     anyhow::{anyhow, Result},
@@ -13,6 +8,12 @@ use {
     },
     std::{ffi::CString, fs::File, io::Read},
 };
+#[cfg(not(any(target_os = "linux", target_os = "android")))]
+use {
+    anyhow::{anyhow, Result},
+    ctor::ctor,
+    std::ffi::CString,
+};
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 fn read_null_lines(path: &str) -> Result<Vec<CString>> {
@@ -102,7 +103,99 @@ fn libnoaslr() -> Result<()> {
     Ok(())
 }
 
-#[cfg(any(target_os = "linux", target_os = "android", target_os = "freebsd"))]
+#[cfg(target_os = "netbsd")]
+fn libnoaslr() -> Result<()> {
+    unsafe {
+        let mut aslr: i32 = 0;
+        let mut s = std::mem::size_of::<i32>();
+        let nm = CString::new("security.pax.aslr.enabled")
+            .map_err(|e| anyhow!("Failed to create sysctl oid: {e:}"))
+            .unwrap();
+        if libc::sysctlbyname(
+            nm.as_ptr(),
+            &mut aslr as *mut i32 as _,
+            &mut s,
+            std::ptr::null(),
+            0,
+        ) < 0
+        {
+            return Err(anyhow!("Failed to get aslr status"));
+        }
+
+        if aslr > 0 {
+            return Err(anyhow!(
+                "Please disable aslr with sysctl -w security.pax.aslr.enabled=0 as privileged user"
+            ));
+        }
+        let mib = &mut [
+            libc::CTL_KERN,
+            libc::KERN_PROC_ARGS,
+            libc::getpid(),
+            libc::KERN_PROC_ARGV,
+        ];
+        let miblen = mib.len() as u32;
+        s = 0;
+        if libc::sysctl(
+            mib.as_mut_ptr(),
+            miblen,
+            std::ptr::null_mut(),
+            &mut s,
+            std::ptr::null_mut(),
+            0,
+        ) < 0
+        {
+            return Err(anyhow!("Failed to get argv buffer"));
+        }
+        let mut pargs: Vec<i8> = Vec::with_capacity(s);
+        if libc::sysctl(
+            mib.as_mut_ptr(),
+            miblen,
+            pargs.as_mut_ptr() as _,
+            &mut s,
+            std::ptr::null_mut(),
+            0,
+        ) < 0
+        {
+            return Err(anyhow!("Failed to get argv"));
+        }
+        mib[3] = libc::KERN_PROC_ENV;
+        s = 0;
+        if libc::sysctl(
+            mib.as_mut_ptr(),
+            miblen,
+            std::ptr::null_mut(),
+            &mut s,
+            std::ptr::null_mut(),
+            0,
+        ) < 0
+        {
+            return Err(anyhow!("Failed to get env buffer"));
+        }
+        let mut penv: Vec<i8> = Vec::with_capacity(s);
+        if libc::sysctl(
+            mib.as_mut_ptr(),
+            miblen,
+            penv.as_mut_ptr() as _,
+            &mut s,
+            std::ptr::null_mut(),
+            0,
+        ) < 0
+        {
+            return Err(anyhow!("Failed to get argv"));
+        }
+        let args = pargs.as_mut_ptr();
+        let env = penv.as_mut_ptr() as _;
+        libc::execvpe(args.add(0) as _, args as _, env);
+    }
+    Ok(())
+}
+
+#[cfg(any(
+    target_os = "linux",
+    target_os = "android",
+    target_os = "freebsd",
+    target_os = "netbsd"
+))]
 #[ctor]
 fn init() {
     libnoaslr().unwrap();

diff --git a/utils/noaslr/noaslr/src/main.rs b/utils/noaslr/noaslr/src/main.rs
@@ -8,7 +8,6 @@ use {
     nix::unistd::execvp,
     std::ffi::CString,
 };
-
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use {
     crate::args::Args,
@@ -60,7 +59,8 @@ fn disable_aslr() -> Result<()> {
             std::ptr::null_mut(),
             &disable as *const i32 as _,
             s,
-        ) < 0 {
+        ) < 0
+        {
             return Err(anyhow!("Failed to disable aslr"));
         }
     }