From 1ea241e4cc9529d45817e448c66f85213778f948 Mon Sep 17 00:00:00 2001 From: Nicolas Lacasse Date: Thu, 17 Dec 2020 11:11:23 -0800 Subject: Fix seek on /proc/pid/cmdline when task is zombie. PiperOrigin-RevId: 348056159 --- pkg/sentry/fsimpl/proc/task_files.go | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'pkg/sentry/fsimpl') diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go index a3780b222..75be6129f 100644 --- a/pkg/sentry/fsimpl/proc/task_files.go +++ b/pkg/sentry/fsimpl/proc/task_files.go @@ -57,9 +57,6 @@ func getMM(task *kernel.Task) *mm.MemoryManager { // MemoryManager's users count is incremented, and must be decremented by the // caller when it is no longer in use. func getMMIncRef(task *kernel.Task) (*mm.MemoryManager, error) { - if task.ExitState() == kernel.TaskExitDead { - return nil, syserror.ESRCH - } var m *mm.MemoryManager task.WithMuLocked(func(t *kernel.Task) { m = t.MemoryManager() @@ -111,9 +108,13 @@ var _ dynamicInode = (*auxvData)(nil) // Generate implements vfs.DynamicBytesSource.Generate. func (d *auxvData) Generate(ctx context.Context, buf *bytes.Buffer) error { + if d.task.ExitState() == kernel.TaskExitDead { + return syserror.ESRCH + } m, err := getMMIncRef(d.task) if err != nil { - return err + // Return empty file. + return nil } defer m.DecUsers(ctx) @@ -157,9 +158,13 @@ var _ dynamicInode = (*cmdlineData)(nil) // Generate implements vfs.DynamicBytesSource.Generate. func (d *cmdlineData) Generate(ctx context.Context, buf *bytes.Buffer) error { + if d.task.ExitState() == kernel.TaskExitDead { + return syserror.ESRCH + } m, err := getMMIncRef(d.task) if err != nil { - return err + // Return empty file. + return nil } defer m.DecUsers(ctx) @@ -472,7 +477,7 @@ func (fd *memFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64 } m, err := getMMIncRef(fd.inode.task) if err != nil { - return 0, nil + return 0, err } defer m.DecUsers(ctx) // Buffer the read data because of MM locks -- cgit v1.2.3