From: Eric W. Biederman Date: Fri, 8 May 2015 21:36:50 +0000 (-0500) Subject: mnt: Fix fs_fully_visible to verify the root directory is visible X-Git-Tag: firefly_0821_release~176^2~1472^2~11 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7e96c1b0e0f495c5a7450dc4aa7c9a24ba4305bd;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: "Eric W. Biederman" --- 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. */