From ad9f4691741cfada0ae09f73053d6195d43465ae Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Fri, 19 Jun 2020 14:39:31 -0700 Subject: Fix bugs in vfs2 to make symlink tests pass. - Return ENOENT if target path is empty. - Make sure open(2) with O_CREAT|O_EXCL returns EEXIST when necessary. - Correctly update atime in tmpfs using touchATime(). Updates #2923. PiperOrigin-RevId: 317382655 --- pkg/sentry/fsimpl/tmpfs/filesystem.go | 7 +++++-- pkg/sentry/syscalls/linux/vfs2/filesystem.go | 3 +++ 2 files changed, 8 insertions(+), 2 deletions(-) (limited to 'pkg/sentry') diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go index ac359cf7b..637d84e04 100644 --- a/pkg/sentry/fsimpl/tmpfs/filesystem.go +++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go @@ -79,7 +79,7 @@ afterSymlink: } if symlink, ok := child.inode.impl.(*symlink); ok && rp.ShouldFollowSymlink() { // Symlink traversal updates access time. - atomic.StoreInt64(&d.inode.atime, d.inode.fs.clock.Now().Nanoseconds()) + child.inode.touchAtime(rp.Mount()) if err := rp.HandleSymlink(symlink.target); err != nil { return nil, err } @@ -372,6 +372,9 @@ afterTrailingSymlink: parentDir.inode.touchCMtime() return fd, nil } + if mustCreate { + return nil, syserror.EEXIST + } // Is the file mounted over? if err := rp.CheckMount(&child.vfsd); err != nil { return nil, err @@ -379,7 +382,7 @@ afterTrailingSymlink: // Do we need to resolve a trailing symlink? if symlink, ok := child.inode.impl.(*symlink); ok && rp.ShouldFollowSymlink() { // Symlink traversal updates access time. - atomic.StoreInt64(&child.inode.atime, child.inode.fs.clock.Now().Nanoseconds()) + child.inode.touchAtime(rp.Mount()) if err := rp.HandleSymlink(symlink.target); err != nil { return nil, err } diff --git a/pkg/sentry/syscalls/linux/vfs2/filesystem.go b/pkg/sentry/syscalls/linux/vfs2/filesystem.go index 46d3e189c..5dac77e4d 100644 --- a/pkg/sentry/syscalls/linux/vfs2/filesystem.go +++ b/pkg/sentry/syscalls/linux/vfs2/filesystem.go @@ -313,6 +313,9 @@ func symlinkat(t *kernel.Task, targetAddr usermem.Addr, newdirfd int32, linkpath if err != nil { return err } + if len(target) == 0 { + return syserror.ENOENT + } linkpath, err := copyInPath(t, linkpathAddr) if err != nil { return err -- cgit v1.2.3