| From | Jiri Slaby <> | Subject | [PATCH 3.12 117/142] mnt: Fix fs_fully_visible to verify the root directory is visible | Date | Sat, 16 May 2015 09:37:57 +0200 |
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From: "Eric W. Biederman" <ebiederm@xmission.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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commit 7e96c1b0e0f495c5a7450dc4aa7c9a24ba4305bd upstream.
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.
Reported-by: Eric Windisch <ewindisch@docker.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- fs/namespace.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/fs/namespace.c b/fs/namespace.c index 7c3c0f6d2744..247f34d43dda 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2940,6 +2940,12 @@ 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. */ -- 2.3.7
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