diff options
| -rw-r--r-- | pkg/sentry/fsimpl/proc/task_files.go | 17 | ||||
| -rw-r--r-- | test/syscalls/linux/proc.cc | 27 |
2 files changed, 38 insertions, 6 deletions
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 diff --git a/test/syscalls/linux/proc.cc b/test/syscalls/linux/proc.cc index 575be014c..e508ce27f 100644 --- a/test/syscalls/linux/proc.cc +++ b/test/syscalls/linux/proc.cc @@ -1802,6 +1802,33 @@ TEST(ProcPidCmdline, SubprocessForkSameCmdline) { } } +TEST(ProcPidCmdline, SubprocessSeekCmdline) { + FileDescriptor fd; + ASSERT_NO_ERRNO(WithSubprocess( + [&](int pid) -> PosixError { + // Running. Open /proc/pid/cmdline. + ASSIGN_OR_RETURN_ERRNO( + fd, Open(absl::StrCat("/proc/", pid, "/cmdline"), O_RDONLY)); + return NoError(); + }, + [&](int pid) -> PosixError { + // Zombie, but seek should still succeed. + int ret = lseek(fd.get(), 0x801, 0); + if (ret < 0) { + return PosixError(errno); + } + return NoError(); + }, + [&](int pid) -> PosixError { + // Exited. + int ret = lseek(fd.get(), 0x801, 0); + if (ret < 0) { + return PosixError(errno); + } + return NoError(); + })); +} + // Test whether /proc/PID/ symlinks can be read for a running process. TEST(ProcPidSymlink, SubprocessRunning) { char buf[1]; |