From 5b2e71dc5b939378303daecab708c4042ee3677d Mon Sep 17 00:00:00 2001 From: TomSweeneyRedHat Date: Sat, 27 Feb 2021 19:53:03 -0500 Subject: 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 --- libpod/container_internal_linux.go | 14 +++++++++++--- test/e2e/run_test.go | 23 ++++++++++++++++++++++- 2 files changed, 33 insertions(+), 4 deletions(-) diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index 24319f4b5..94c6c3840 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -1503,16 +1503,24 @@ func (c *Container) makeBindMounts() error { } // Make /etc/localtime - if c.Timezone() != "" { + ctrTimezone := c.Timezone() + if ctrTimezone != "" { + // validate the format of the timezone specified if it's not "local" + if ctrTimezone != "local" { + _, err = time.LoadLocation(ctrTimezone) + if err != nil { + return errors.Wrapf(err, "error finding timezone for container %s", c.ID()) + } + } if _, ok := c.state.BindMounts["/etc/localtime"]; !ok { var zonePath string - if c.Timezone() == "local" { + if ctrTimezone == "local" { zonePath, err = filepath.EvalSymlinks("/etc/localtime") if err != nil { return errors.Wrapf(err, "error finding local timezone for container %s", c.ID()) } } else { - zone := filepath.Join("/usr/share/zoneinfo", c.Timezone()) + zone := filepath.Join("/usr/share/zoneinfo", ctrTimezone) zonePath, err = filepath.EvalSymlinks(zone) if err != nil { return errors.Wrapf(err, "error setting timezone for container %s", c.ID()) 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))) -- cgit v1.2.3-54-g00ecf