diff options
| -rw-r--r-- | fs/namespace.c | 25 |
1 files changed, 8 insertions, 17 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 2e13f6cfe5df..b1da7f8182c4 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3232,12 +3232,8 @@ static bool mnt_already_visible(struct mnt_namespace *ns, struct vfsmount *new, if (mnt->mnt.mnt_root != mnt->mnt.mnt_sb->s_root) continue; - /* Read the mount flags and filter out flags that - * may safely be ignored. - */ + /* A local view of the mount flags */ mnt_flags = mnt->mnt.mnt_flags; - if (mnt->mnt.mnt_sb->s_iflags & SB_I_NOEXEC) - mnt_flags &= ~(MNT_LOCK_NOSUID | MNT_LOCK_NOEXEC); /* Don't miss readonly hidden in the superblock flags */ if (mnt->mnt.mnt_sb->s_flags & MS_RDONLY) @@ -3249,15 +3245,6 @@ static bool mnt_already_visible(struct mnt_namespace *ns, struct vfsmount *new, if ((mnt_flags & MNT_LOCK_READONLY) && !(new_flags & MNT_READONLY)) continue; - if ((mnt_flags & MNT_LOCK_NODEV) && - !(new_flags & MNT_NODEV)) - continue; - if ((mnt_flags & MNT_LOCK_NOSUID) && - !(new_flags & MNT_NOSUID)) - continue; - if ((mnt_flags & MNT_LOCK_NOEXEC) && - !(new_flags & MNT_NOEXEC)) - continue; if ((mnt_flags & MNT_LOCK_ATIME) && ((mnt_flags & MNT_ATIME_MASK) != (new_flags & MNT_ATIME_MASK))) continue; @@ -3277,9 +3264,6 @@ static bool mnt_already_visible(struct mnt_namespace *ns, struct vfsmount *new, } /* Preserve the locked attributes */ *new_mnt_flags |= mnt_flags & (MNT_LOCK_READONLY | \ - MNT_LOCK_NODEV | \ - MNT_LOCK_NOSUID | \ - MNT_LOCK_NOEXEC | \ MNT_LOCK_ATIME); visible = true; goto found; @@ -3292,6 +3276,7 @@ found: static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags) { + const unsigned long required_iflags = SB_I_NOEXEC | SB_I_NODEV; struct mnt_namespace *ns = current->nsproxy->mnt_ns; unsigned long s_iflags; @@ -3303,6 +3288,12 @@ static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags) if (!(s_iflags & SB_I_USERNS_VISIBLE)) return false; + if ((s_iflags & required_iflags) != required_iflags) { + WARN_ONCE(1, "Expected s_iflags to contain 0x%lx\n", + required_iflags); + return true; + } + return !mnt_already_visible(ns, mnt, new_mnt_flags); } |