From d93d19fd4eefdfd868919a73c9498e7da7eb9258 Mon Sep 17 00:00:00 2001 From: Nicolas Lacasse Date: Wed, 10 Apr 2019 16:35:22 -0700 Subject: Fix uses of RootFromContext. RootFromContext can return a dirent with reference taken, or nil. We must call DecRef if (and only if) a real dirent is returned. PiperOrigin-RevId: 242965515 Change-Id: Ie2b7b4cb19ee09b6ccf788b71f3fd7efcdf35a11 --- pkg/sentry/fs/proc/fds.go | 4 +++- pkg/sentry/fs/proc/proc.go | 4 +++- pkg/sentry/fs/proc/task.go | 4 +++- 3 files changed, 9 insertions(+), 3 deletions(-) (limited to 'pkg/sentry/fs/proc') diff --git a/pkg/sentry/fs/proc/fds.go b/pkg/sentry/fs/proc/fds.go index b8a0a5eff..3c471bad9 100644 --- a/pkg/sentry/fs/proc/fds.go +++ b/pkg/sentry/fs/proc/fds.go @@ -119,7 +119,9 @@ func (f *fd) GetFile(context.Context, *fs.Dirent, fs.FileFlags) (*fs.File, error // Readlink returns the current target. func (f *fd) Readlink(ctx context.Context, _ *fs.Inode) (string, error) { root := fs.RootFromContext(ctx) - defer root.DecRef() + if root != nil { + defer root.DecRef() + } n, _ := f.Dirent.FullName(root) return n, nil } diff --git a/pkg/sentry/fs/proc/proc.go b/pkg/sentry/fs/proc/proc.go index 88018e707..c9e659533 100644 --- a/pkg/sentry/fs/proc/proc.go +++ b/pkg/sentry/fs/proc/proc.go @@ -210,7 +210,9 @@ func (rpf *rootProcFile) Readdir(ctx context.Context, file *fs.File, ser fs.Dent // Add dot and dotdot. root := fs.RootFromContext(ctx) - defer root.DecRef() + if root != nil { + defer root.DecRef() + } dot, dotdot := file.Dirent.GetDotAttrs(root) names = append(names, ".", "..") m["."] = dot diff --git a/pkg/sentry/fs/proc/task.go b/pkg/sentry/fs/proc/task.go index 5a90c5578..4b1f84942 100644 --- a/pkg/sentry/fs/proc/task.go +++ b/pkg/sentry/fs/proc/task.go @@ -162,7 +162,9 @@ func (f *subtasksFile) Readdir(ctx context.Context, file *fs.File, ser fs.Dentry if offset == 0 { // Serialize "." and "..". root := fs.RootFromContext(ctx) - defer root.DecRef() + if root != nil { + defer root.DecRef() + } dot, dotdot := file.Dirent.GetDotAttrs(root) if err := dirCtx.DirEmit(".", dot); err != nil { return offset, err -- cgit v1.2.3