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authorEric W. Biederman <ebiederm@xmission.com>2015-05-08 16:36:50 -0500
committerEric W. Biederman <ebiederm@xmission.com>2015-05-09 11:55:50 -0500
commit7e96c1b0e0f495c5a7450dc4aa7c9a24ba4305bd (patch)
tree359383086b15aa2d27e543d51865886d51d2bb23
parentLinux 4.1-rc1 (diff)
downloadlinux-dev-7e96c1b0e0f495c5a7450dc4aa7c9a24ba4305bd.tar.xz
linux-dev-7e96c1b0e0f495c5a7450dc4aa7c9a24ba4305bd.zip
mnt: Fix fs_fully_visible to verify the root directory is visible
This fixes a dumb bug in fs_fully_visible that allows proc or sys to be mounted if there is a bind mount of part of /proc/ or /sys/ visible. Cc: stable@vger.kernel.org Reported-by: Eric Windisch <ewindisch@docker.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
-rw-r--r--fs/namespace.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 1f4f9dac6e5a..1b9e11167bae 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -3179,6 +3179,12 @@ bool fs_fully_visible(struct file_system_type *type)
if (mnt->mnt.mnt_sb->s_type != type)
continue;
+ /* This mount is not fully visible if it's root directory
+ * is not the root directory of the filesystem.
+ */
+ if (mnt->mnt.mnt_root != mnt->mnt.mnt_sb->s_root)
+ continue;
+
/* This mount is not fully visible if there are any child mounts
* that cover anything except for empty directories.
*/