From 511c1eb5b2fe20fa3a46277fd883a79eb0f99d7a Mon Sep 17 00:00:00 2001
From: Alan Somers <asomers@gmail.com>
Date: Sat, 16 May 2020 16:13:12 -0600
Subject: [PATCH] Fix an unaligned pointer read in Inotify::read_events

Reported-by: Clippy
---
 CHANGELOG.md       |  2 ++
 src/sys/inotify.rs | 18 +++++++++++-------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e186d94630..e674e3fe38 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -46,6 +46,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   16KB. (#[1198](https://github.com/nix-rust/nix/pull/1198))
 - Fixed unaligned casting of `cmsg_data` to `af_alg_iv` (#[1206](https://github.com/nix-rust/nix/pull/1206))
 - Fixed `readlink`/`readlinkat` when reading symlinks longer than `PATH_MAX` (#[1231](https://github.com/nix-rust/nix/pull/1231))
+- Fixed unaligned pointer read in `Inotify::read_events`.
+  (#[1244](https://github.com/nix-rust/nix/pull/1244))
 
 ### Removed
 
diff --git a/src/sys/inotify.rs b/src/sys/inotify.rs
index e6c2cf64d2..9b544b90e4 100644
--- a/src/sys/inotify.rs
+++ b/src/sys/inotify.rs
@@ -30,8 +30,9 @@ use libc::{
 };
 use std::ffi::{OsString,OsStr,CStr};
 use std::os::unix::ffi::OsStrExt;
-use std::mem::size_of;
+use std::mem::{MaybeUninit, size_of};
 use std::os::unix::io::{RawFd,AsRawFd,FromRawFd};
+use std::ptr;
 use unistd::read;
 use Result;
 use NixPath;
@@ -173,7 +174,8 @@ impl Inotify {
     /// events could be read then the EAGAIN error is returned.
     pub fn read_events(&self) -> Result<Vec<InotifyEvent>> {
         let header_size = size_of::<libc::inotify_event>();
-        let mut buffer = [0u8; 4096];
+        const BUFSIZ: usize = 4096;
+        let mut buffer = [0u8; BUFSIZ];
         let mut events = Vec::new();
         let mut offset = 0;
 
@@ -181,11 +183,13 @@ impl Inotify {
 
         while (nread - offset) >= header_size {
             let event = unsafe {
-                &*(
-                    buffer
-                        .as_ptr()
-                        .offset(offset as isize) as *const libc::inotify_event
-                )
+                let mut event = MaybeUninit::<libc::inotify_event>::uninit();
+                ptr::copy_nonoverlapping(
+                    buffer.as_ptr().offset(offset as isize),
+                    event.as_mut_ptr() as *mut u8,
+                    (BUFSIZ - offset).min(header_size)
+                );
+                event.assume_init()
             };
 
             let name = match event.len {