From 62db1fad2cb7d2249720e157aa79c84b7531a2e9 Mon Sep 17 00:00:00 2001 From: Jamie Liu Date: Thu, 12 Nov 2020 18:20:30 -0800 Subject: Fix misuses of kernel.Task as context.Context. kernel.Task can only be used as context.Context by that Task's task goroutine. This is violated in at least two places: - In any case where one thread accesses the /proc/[tid] of any other thread, passing the kernel.Task for [tid] as the context.Context is incorrect. - Task.rebuildTraceContext() may be called by Kernel.RebuildTraceContexts() outside the scope of any task goroutine. Fix these (as well as a data race on Task.traceContext discovered during the course of finding the latter). PiperOrigin-RevId: 342174404 --- pkg/sentry/fsimpl/proc/subtasks.go | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'pkg/sentry/fsimpl/proc/subtasks.go') diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go index e001d5032..c53cc0122 100644 --- a/pkg/sentry/fsimpl/proc/subtasks.go +++ b/pkg/sentry/fsimpl/proc/subtasks.go @@ -50,7 +50,7 @@ type subtasksInode struct { var _ kernfs.Inode = (*subtasksInode)(nil) -func (fs *filesystem) newSubtasks(task *kernel.Task, pidns *kernel.PIDNamespace, cgroupControllers map[string]string) kernfs.Inode { +func (fs *filesystem) newSubtasks(ctx context.Context, task *kernel.Task, pidns *kernel.PIDNamespace, cgroupControllers map[string]string) kernfs.Inode { subInode := &subtasksInode{ fs: fs, task: task, @@ -58,7 +58,7 @@ func (fs *filesystem) newSubtasks(task *kernel.Task, pidns *kernel.PIDNamespace, cgroupControllers: cgroupControllers, } // Note: credentials are overridden by taskOwnedInode. - subInode.InodeAttrs.Init(task, task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) + subInode.InodeAttrs.Init(ctx, task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) subInode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) subInode.InitRefs() @@ -80,7 +80,7 @@ func (i *subtasksInode) Lookup(ctx context.Context, name string) (kernfs.Inode, if subTask.ThreadGroup() != i.task.ThreadGroup() { return nil, syserror.ENOENT } - return i.fs.newTaskInode(subTask, i.pidns, false, i.cgroupControllers) + return i.fs.newTaskInode(ctx, subTask, i.pidns, false, i.cgroupControllers) } // IterDirents implements kernfs.inodeDirectory.IterDirents. -- cgit v1.2.3