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

1 files changed, 3 insertions, 3 deletions

diff --git a/pkg/sentry/fs/proc/exec_args.go b/pkg/sentry/fs/proc/exec_args.go
index 8fe626e1c..e6171dd1d 100644
--- a/pkg/sentry/fs/proc/exec_args.go
+++ b/pkg/sentry/fs/proc/exec_args.go
@@ -57,16 +57,16 @@ type execArgInode struct {
 var _ fs.InodeOperations = (*execArgInode)(nil)
 
 // newExecArgFile creates a file containing the exec args of the given type.
-func newExecArgInode(t *kernel.Task, msrc *fs.MountSource, arg execArgType) *fs.Inode {
+func newExecArgInode(ctx context.Context, t *kernel.Task, msrc *fs.MountSource, arg execArgType) *fs.Inode {
 	if arg != cmdlineExecArg && arg != environExecArg {
 		panic(fmt.Sprintf("unknown exec arg type %v", arg))
 	}
 	f := &execArgInode{
-		SimpleFileInode: *fsutil.NewSimpleFileInode(t, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC),
+		SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC),
 		arg:             arg,
 		t:               t,
 	}
-	return newProcInode(t, f, msrc, fs.SpecialFile, t)
+	return newProcInode(ctx, f, msrc, fs.SpecialFile, t)
 }
 
 // GetFile implements fs.InodeOperations.GetFile.