fix: correctly decode WSL2 Docker mounts

procfs-core/src/mounts.rs

@@ -31,12 +31,26 @@ impl super::FromBufRead for Vec<MountEntry> {
 
         for line in r.lines() {
             let line = expect!(line);
-            let mut s = line.split(' '); // not using split_whitespace because we might have empty fields
 
-            let fs_spec = unmangle_octal(expect!(s.next()));
-            let fs_file = unmangle_octal(expect!(s.next()));
-            let fs_vfstype = unmangle_octal(expect!(s.next()));
-            let fs_mntops = unmangle_octal(expect!(s.next()));
+            // The format is `fs_spec fs_file fs_vfstype fs_mntops fs_freq fs_passno`.
+            // Each field is normally space-mangled (e.g. `\040` for a literal space),
+            // so a plain split on ' ' would yield six fields. In practice some
+            // drivers emit `fs_mntops` with unescaped spaces inside option values
+            // (notably the 9p mount Docker Desktop on WSL2 creates, where the
+            // option string contains `path=C:\Program Files\...`). To stay robust
+            // to that, take the first three fields from the front and the last two
+            // from the back; whatever is left in between is `fs_mntops`.
+            let mut head = line.splitn(4, ' ');
+            let fs_spec = unmangle_octal(expect!(head.next()));
+            let fs_file = unmangle_octal(expect!(head.next()));
+            let fs_vfstype = unmangle_octal(expect!(head.next()));
+            let rest = expect!(head.next());
+
+            let mut tail = rest.rsplitn(3, ' ');
+            let fs_passno = expect!(u8::from_str(expect!(tail.next())));
+            let fs_freq = expect!(u8::from_str(expect!(tail.next())));
+            let fs_mntops = unmangle_octal(expect!(tail.next()));
+
             let fs_mntops: HashMap<String, Option<String>> = fs_mntops
                 .split(',')
                 .map(|s| {
@@ -47,8 +61,6 @@ impl super::FromBufRead for Vec<MountEntry> {
                     (k, v)
                 })
                 .collect();
-            let fs_freq = expect!(u8::from_str(expect!(s.next())));
-            let fs_passno = expect!(u8::from_str(expect!(s.next())));
 
             let mount_entry = MountEntry {
                 fs_spec,
@@ -66,13 +78,14 @@ impl super::FromBufRead for Vec<MountEntry> {
     }
 }
 
+
 /// Unmangle spaces ' ', tabs '\t', line breaks '\n', backslashes '\\', and hashes '#'
 ///
 /// See https://elixir.bootlin.com/linux/v6.2.8/source/fs/proc_namespace.c#L89
 pub(crate) fn unmangle_octal(input: &str) -> String {
     let mut input = input.to_string();
 
-    for (octal, c) in [(r"\011", "\t"), (r"\012", "\n"), (r"\134", "\\"), (r"\043", "#")] {
+    for (octal, c) in [(r"\040", " "), (r"\011", "\t"), (r"\012", "\n"), (r"\134", "\\"), (r"\043", "#")] {
         input = input.replace(octal, c);
     }
 
@@ -114,3 +127,21 @@ Downloads /media/sf_downloads vboxsf rw,nodev,relatime,iocharset=utf8,uid=0,gid=
     assert_eq!(mounts[0].fs_vfstype, "tmpfs");
     assert!(mounts[0].fs_mntops.contains_key("ro"));
 }
+
+#[test]
+fn test_unescaped_spaces_in_mntops() {
+    // Docker Desktop on WSL2 emits 9p mount lines with literal spaces inside
+    // `path=...` in fs_mntops; the parser must tolerate them.
+    let raw = b"C:\\134Program\\040Files\\134Docker\\134Docker\\134resources /Docker/host 9p rw,noatime,aname=drvfs;path=C:\\Program Files\\Docker\\Docker\\resources;symlinkroot=/mnt/,cache=5,access=client,msize=65536,trans=fd,rfd=3,wfd=3 0 0\n";
+    let mounts = <Vec<MountEntry> as crate::FromBufRead>::from_buf_read(&raw[..]).unwrap();
+    assert_eq!(mounts.len(), 1);
+    let m = &mounts[0];
+    assert_eq!(m.fs_spec, r"C:\Program Files\Docker\Docker\resources");
+    assert_eq!(m.fs_file, "/Docker/host");
+    assert_eq!(m.fs_vfstype, "9p");
+    assert_eq!(m.fs_freq, 0);
+    assert_eq!(m.fs_passno, 0);
+    assert_eq!(m.fs_mntops.get("cache").unwrap().as_deref(), Some("5"));
+    // The space-bearing value is preserved end-to-end.
+    assert!(m.fs_mntops.get("aname").unwrap().as_deref().unwrap().contains("C:\\Program Files\\Docker"));
+}