fixes for CVE-2019-16884 #28
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Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Fixes #2128 This allows proc to be bind mounted for host and rootless namespace usecases but it removes the ability to mount over the top of proc with a directory. ```bash > sudo docker run --rm apparmor docker: Error response from daemon: OCI runtime create failed: container_linux.go:346: starting container process caused "process_linux.go:449: container init caused \"rootfs_linux.go:58: mounting \\\"/var/lib/docker/volumes/aae28ea068c33d60e64d1a75916cf3ec2dc3634f97571854c9ed30c8401460c1/_data\\\" to rootfs \\\"/var/lib/docker/overlay2/a6be5ae911bf19f8eecb23a295dec85be9a8ee8da66e9fb55b47c841d1e381b7/merged\\\" at \\\"/proc\\\" caused \\\"\\\\\\\"/var/lib/docker/overlay2/a6be5ae911bf19f8eecb23a295dec85be9a8ee8da66e9fb55b47c841d1e381b7/merged/proc\\\\\\\" cannot be mounted because it is not of type proc\\\"\"": unknown. > sudo docker run --rm -v /proc:/proc apparmor docker-default (enforce) root 18989 0.9 0.0 1288 4 ? Ss 16:47 0:00 sleep 20 ``` Signed-off-by: Michael Crosby <crosbymichael@gmail.com> (cherry picked from commit 331692b)
This is a bump to v1.3.0, plus the necessary CVE-2019-16884 mitigation. Signed-off-by: Aleksa Sarai <asarai@suse.de> (cherry picked from commit 9aef504)
This is an additional mitigation for CVE-2019-16884. The primary problem is that Docker can be coerced into bind-mounting a file system on top of /proc (resulting in label-related writes to /proc no longer happening). While we are working on mitigations against permitting the mounts, this helps avoid our code from being tricked into writing to non-procfs files. This is not a perfect solution (after all, there might be a bind-mount of a different procfs file over the target) but in order to exploit that you would need to be able to tweak a config.json pretty specifically (which thankfully Docker doesn't allow). Specifically this stops AppArmor from not labeling a process silently due to /proc/self/attr/... being incorrectly set, and stops any accidental fd leaks because /proc/self/fd/... is not real. Signed-off-by: Aleksa Sarai <asarai@suse.de> (cherry picked from commit d463f64)
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LGTM |
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dropped the WIP |
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@edsantiago PTAL |
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I don't think I can help here. I don't know enough about runc to review the proposed changes; and I can't reproduce the SELinux vulnerability on Fedora, not even with runc -93 nor with crun, so I can't even write test cases. I'm sorry. |
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Ok I will merge, as I think this fixes this issue. |
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Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1757214