From b5b7ff1643dc7ddc5f5414e40016e0b302782d2b Mon Sep 17 00:00:00 2001
From: Grimmauld <soeren@benjos.de>
Date: Sat, 27 Dec 2025 18:32:15 +0100
Subject: [PATCH] Allow access to arbitrary files if CAP_DAC_OVERRIDE is set on
 Linux (#15024)

---
 helix-stdx/Cargo.toml     | 2 +-
 helix-stdx/src/faccess.rs | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/helix-stdx/Cargo.toml b/helix-stdx/Cargo.toml
index 66d02925..7fa471fe 100644
--- a/helix-stdx/Cargo.toml
+++ b/helix-stdx/Cargo.toml
@@ -26,7 +26,7 @@ unicode-segmentation.workspace = true
 windows-sys = { version = "0.61", features = ["Win32_Foundation", "Win32_Security", "Win32_Security_Authorization", "Win32_Storage_FileSystem", "Win32_System_Threading"] }
 
 [target.'cfg(unix)'.dependencies]
-rustix = { version = "1.1", features = ["fs"] }
+rustix = { version = "1.1", features = ["fs", "thread"] }
 
 [dev-dependencies]
 tempfile.workspace = true
diff --git a/helix-stdx/src/faccess.rs b/helix-stdx/src/faccess.rs
index b98ae153..d5bb10b2 100644
--- a/helix-stdx/src/faccess.rs
+++ b/helix-stdx/src/faccess.rs
@@ -29,6 +29,15 @@ mod imp {
     use std::os::unix::fs::{MetadataExt, PermissionsExt};
 
     pub fn access(p: &Path, mode: AccessMode) -> io::Result<()> {
+        #[cfg(target_os = "linux")]
+        {
+            // If helix has ambient CAP_DAC_OVERRIDE, everything is accessible regardless of mode bits
+            use rustix::thread::{capability_is_in_ambient_set, CapabilitySet};
+            if capability_is_in_ambient_set(CapabilitySet::DAC_OVERRIDE).unwrap_or(false) {
+                return Ok(());
+            }
+        }
+
         let mut imode = Access::empty();
 
         if mode.contains(AccessMode::EXISTS) {
-- 
2.51.2