run: Don't allow unmounting filesystems

If we don't allow mounting filesystems, we shouldn't allow unmounting either. Partially fixes GHSA-67h7-w3jq-vh4q. Signed-off-by: Simon McVittie <[email protected]> (cherry picked from commit 758b8ca)
debarshiray · Nov 2, 2021 · 5f5b4d5 · 5f5b4d5
1 parent 36094ca
commit 5f5b4d5
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
@@ -2621,6 +2621,8 @@ setup_seccomp (FlatpakBwrap   *bwrap,
     {SCMP_SYS (unshare), EPERM},
     {SCMP_SYS (setns), EPERM},
     {SCMP_SYS (mount), EPERM},
+    {SCMP_SYS (umount), EPERM},
+    {SCMP_SYS (umount2), EPERM},
     {SCMP_SYS (pivot_root), EPERM},
 #if defined(__s390__) || defined(__s390x__) || defined(__CRIS__)
     /* Architectures with CONFIG_CLONE_BACKWARDS2: the child stack