Merge pull request from GHSA-qvf8-p83w-v58j

do not set the inheritable capabilities
This commit is contained in:
Giuseppe Scrivano 2022-03-24 17:02:20 +01:00 committed by GitHub
commit ab8e15f6ac
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GPG key ID: 4AEE18F83AFDEB23
3 changed files with 13 additions and 7 deletions

View file

@ -758,11 +758,14 @@ func prepareProcessExec(c *Container, options *ExecOptions, env []string, sessio
} else {
pspec.Capabilities.Bounding = ctrSpec.Process.Capabilities.Bounding
}
// Always unset the inheritable capabilities similarly to what the Linux kernel does
// They are used only when using capabilities with uid != 0.
pspec.Capabilities.Inheritable = []string{}
if execUser.Uid == 0 {
pspec.Capabilities.Effective = pspec.Capabilities.Bounding
pspec.Capabilities.Inheritable = pspec.Capabilities.Bounding
pspec.Capabilities.Permitted = pspec.Capabilities.Bounding
pspec.Capabilities.Ambient = pspec.Capabilities.Bounding
} else {
if user == c.config.User {
pspec.Capabilities.Effective = ctrSpec.Process.Capabilities.Effective

View file

@ -146,6 +146,10 @@ func securityConfigureGenerator(s *specgen.SpecGenerator, g *generate.Generator,
configSpec := g.Config
configSpec.Process.Capabilities.Ambient = []string{}
// Always unset the inheritable capabilities similarly to what the Linux kernel does
// They are used only when using capabilities with uid != 0.
configSpec.Process.Capabilities.Inheritable = []string{}
configSpec.Process.Capabilities.Bounding = caplist
user := strings.Split(s.User, ":")[0]
@ -153,7 +157,6 @@ func securityConfigureGenerator(s *specgen.SpecGenerator, g *generate.Generator,
if (user == "" && s.UserNS.NSMode != specgen.KeepID) || user == "root" || user == "0" {
configSpec.Process.Capabilities.Effective = caplist
configSpec.Process.Capabilities.Permitted = caplist
configSpec.Process.Capabilities.Inheritable = caplist
} else {
mergedCaps, err := capabilities.MergeCapabilities(nil, s.CapAdd, nil)
if err != nil {
@ -175,12 +178,12 @@ func securityConfigureGenerator(s *specgen.SpecGenerator, g *generate.Generator,
}
configSpec.Process.Capabilities.Effective = userCaps
configSpec.Process.Capabilities.Permitted = userCaps
configSpec.Process.Capabilities.Inheritable = userCaps
// Ambient capabilities were added to Linux 4.3. Set ambient
// capabilities only when the kernel supports them.
if supportAmbientCapabilities() {
configSpec.Process.Capabilities.Ambient = userCaps
configSpec.Process.Capabilities.Inheritable = userCaps
}
}

View file

@ -498,7 +498,7 @@ var _ = Describe("Podman run", func() {
session = podmanTest.Podman([]string{"run", "--rm", "--user", "root", ALPINE, "grep", "CapInh", "/proc/self/status"})
session.WaitWithDefaultTimeout()
Expect(session).Should(Exit(0))
Expect(session.OutputToString()).To(ContainSubstring("00000000a80425fb"))
Expect(session.OutputToString()).To(ContainSubstring("0000000000000000"))
session = podmanTest.Podman([]string{"run", "--rm", ALPINE, "grep", "CapBnd", "/proc/self/status"})
session.WaitWithDefaultTimeout()
@ -533,7 +533,7 @@ var _ = Describe("Podman run", func() {
session = podmanTest.Podman([]string{"run", "--user=0:0", "--cap-add=DAC_OVERRIDE", "--rm", ALPINE, "grep", "CapInh", "/proc/self/status"})
session.WaitWithDefaultTimeout()
Expect(session).Should(Exit(0))
Expect(session.OutputToString()).To(ContainSubstring("00000000a80425fb"))
Expect(session.OutputToString()).To(ContainSubstring("0000000000000000"))
if os.Geteuid() > 0 {
if os.Getenv("SKIP_USERNS") != "" {
@ -550,7 +550,7 @@ var _ = Describe("Podman run", func() {
session = podmanTest.Podman([]string{"run", "--userns=keep-id", "--privileged", "--rm", ALPINE, "grep", "CapInh", "/proc/self/status"})
session.WaitWithDefaultTimeout()
Expect(session).Should(Exit(0))
Expect(session.OutputToString()).To(ContainSubstring("0000000000000000"))
Expect(session.OutputToString()).To(ContainSubstring("0000000000000002"))
session = podmanTest.Podman([]string{"run", "--userns=keep-id", "--cap-add=DAC_OVERRIDE", "--rm", ALPINE, "grep", "CapInh", "/proc/self/status"})
session.WaitWithDefaultTimeout()