vendor: github.com/moby/sys/userns v0.2.0

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor.mod

@@ -90,7 +90,7 @@ require (
 	github.com/klauspost/compress v1.18.7 // indirect
 	github.com/moby/docker-image-spec v1.3.1 // indirect
 	github.com/moby/sys/user v0.4.1 // indirect
-	github.com/moby/sys/userns v0.1.0 // indirect
+	github.com/moby/sys/userns v0.2.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/prometheus/client_golang v1.22.0 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect

vendor.sum

@@ -134,8 +134,8 @@ github.com/moby/sys/symlink v0.3.0 h1:GZX89mEZ9u53f97npBy4Rc3vJKj7JBDj/PN2I22GrN
 github.com/moby/sys/symlink v0.3.0/go.mod h1:3eNdhduHmYPcgsJtZXW1W4XUJdZGBIkttZ8xKqPUJq0=
 github.com/moby/sys/user v0.4.1 h1:RgjRlaDKi/Xmyrz4t8lyzXT6v2ooFeO/7xtchmhVWE0=
 github.com/moby/sys/user v0.4.1/go.mod h1:E9QsW5WRe1kUAf7kW8hXKwu1uhsZEAdPLYHYSDudF4Y=
-github.com/moby/sys/userns v0.1.0 h1:tVLXkFOxVu9A64/yh59slHVv9ahO9UIev4JZusOLG/g=
-github.com/moby/sys/userns v0.1.0/go.mod h1:IHUYgu/kao6N8YZlp9Cf444ySSvCmDlmzUcYfDHOl28=
+github.com/moby/sys/userns v0.2.0 h1:nEtDtp7NCV/6dutSklNe8FrENPwFdc4mXnZqC/JWgXM=
+github.com/moby/sys/userns v0.2.0/go.mod h1:IHUYgu/kao6N8YZlp9Cf444ySSvCmDlmzUcYfDHOl28=
 github.com/moby/term v0.5.2 h1:6qk3FJAFDs6i/q3W/pQ97SX192qKfZgGjCQqfCJkgzQ=
 github.com/moby/term v0.5.2/go.mod h1:d3djjFCrjnB+fl8NJux+EJzu0msscUP+f8it8hPkFLc=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=

vendor/github.com/moby/sys/userns/userns_linux.go

@@ -5,8 +5,12 @@ import (
 	"fmt"
 	"os"
 	"sync"
+	"syscall"
 )
 
+// See PROC_USER_INIT_INO in https://github.com/torvalds/linux/blob/v7.1/include/uapi/linux/nsfs.h#L50.
+const procUserInitIno = 0xEFFFFFFD
+
 var inUserNS = sync.OnceValue(runningInUserNS)
 
 // runningInUserNS detects whether we are currently running in a user namespace.
@@ -17,6 +21,20 @@ var inUserNS = sync.OnceValue(runningInUserNS)
 // [libcontainer/runc]: https://github.com/opencontainers/runc/blob/3778ae603c706494fd1e2c2faf83b406e38d687d/libcontainer/userns/userns_linux.go#L12-L49
 // [lcx/incus]: https://github.com/lxc/incus/blob/e45085dd42f826b3c8c3228e9733c0b6f998eafe/shared/util.go#L678-L700
 func runningInUserNS() bool {
+	var st syscall.Stat_t
+	if err := syscall.Stat("/proc/self/ns/user", &st); err == nil {
+		return st.Ino != procUserInitIno
+	} else if !os.IsNotExist(err) {
+		// As long as /proc/self/ns/user exists, we are on a modern kernel.
+		// Other errors indicate an unexpected procfs state, where assuming the
+		// init namespace would be unsafe.
+		return false
+	}
+
+	// Only fall back for older kernels that do not expose the user namespace
+	// through procfs at /proc/self/ns/user.
+	// TODO: Remove this fallback once Linux kernels older than 3.8 are no
+	// longer supported.
 	file, err := os.Open("/proc/self/uid_map")
 	if err != nil {
 		// This kernel-provided file only exists if user namespaces are supported.

vendor/modules.txt

@@ -231,7 +231,7 @@ github.com/moby/sys/symlink
 # github.com/moby/sys/user v0.4.1
 ## explicit; go 1.18
 github.com/moby/sys/user
-# github.com/moby/sys/userns v0.1.0
+# github.com/moby/sys/userns v0.2.0
 ## explicit; go 1.21
 github.com/moby/sys/userns
 # github.com/moby/term v0.5.2