Validate passed in timezone from tz option

Erik Sjolund reported an issue where a badly formated file
could be passed into the `--tz` option and then the date in the container
would be badly messed up:

```
erik@laptop:~$ echo Hello > file.txt
erik@laptop:~$ podman run --tz=../../../home/erik/file.txt --rm -ti
docker.io/library/alpine cat /etc/localtime
Hello
erik@laptop:~$ podman --version
podman version 3.0.0-rc1
erik@laptop:~$
```
This fix checks to make sure the TZ passed in is a valid
value and then proceeds with the rest of the processing.

This was first reported as a potential security issue, but it
was thought not to be.   However, I thought closing the hole
sooner rather than later would be good.

Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/test/e2e/run_test.go b/test/e2e/run_test.go
index 4e5106731..bb1f9590d 100644
--- a/test/e2e/run_test.go
+++ b/test/e2e/run_test.go
@@ -1412,7 +1412,28 @@ USER mail`
 	})
 
 	It("podman run --tz", func() {
-		session := podmanTest.Podman([]string{"run", "--tz", "foo", "--rm", ALPINE, "date"})
+		testDir := filepath.Join(podmanTest.RunRoot, "tz-test")
+		err := os.MkdirAll(testDir, 0755)
+		Expect(err).To(BeNil())
+
+		tzFile := filepath.Join(testDir, "tzfile.txt")
+		file, err := os.Create(tzFile)
+		Expect(err).To(BeNil())
+
+		_, err = file.WriteString("Hello")
+		Expect(err).To(BeNil())
+		file.Close()
+
+		badTZFile := fmt.Sprintf("../../../%s", tzFile)
+		session := podmanTest.Podman([]string{"run", "--tz", badTZFile, "--rm", ALPINE, "date"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Not(Equal(0)))
+		Expect(session.ErrorToString()).To(ContainSubstring("error finding timezone for container"))
+
+		err = os.Remove(tzFile)
+		Expect(err).To(BeNil())
+
+		session = podmanTest.Podman([]string{"run", "--tz", "foo", "--rm", ALPINE, "date"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Not(Equal(0)))