From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Andrew Udvare Date: Sat, 10 Oct 2026 05:26:16 -0400 Subject: [PATCH] Restore the working directory after joining the mount namespace setns() with CLONE_NEWNS moves the caller to the root of the new mount namespace. The launcher then resolved its program argument with realpath() relative to /, so `darling ./program` and `darling program` failed with "is not a supported command or a file". The container's mount namespace is a copy of the host's, so change back to the original working directory after joining it. Signed-off-by: Andrew Udvare --- src/startup/darling.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/startup/darling.c b/src/startup/darling.c index a3f27fbf3..0452c685d 100644 --- a/src/startup/darling.c +++ b/src/startup/darling.c @@ -188,6 +188,10 @@ int main(int argc, char ** argv) #if USE_LINUX_4_11_HACK joinNamespace(pidInit, CLONE_NEWNS, "mnt"); + // setns() moves us to the root of the mount namespace; restore the working directory so that + // relative paths (e.g. `darling ./program`) still resolve + if (chdir(g_workingDirectory) != 0) + fprintf(stderr, "Cannot change to %s: %s\n", g_workingDirectory, strerror(errno)); #endif seteuid(g_originalUid);