Re: [PATCH v6 00/16] Infrastructure to allow fixing exec deadlocks

[ebiederm@xmission.com (Eric W. Biederman)]

Bernd Edlinger <bernd.edlinger@hotmail.de> writes:

> This is an infrastructure change that makes way for fixing this issue.
> Each patch was already posted previously so this is just a cleanup of
> the original mailing list thread(s) which got out of control by now.
>
> Everything started here:
> https://lore.kernel.org/lkml/AM6PR03MB5170B06F3A2B75EFB98D071AE4E60@AM6PR03MB5170.eurprd03.prod.outlook.com/
>
> I added reviewed-by tags from the mailing list threads, except when
> withdrawn.
>
> It took a lot longer than expected to collect everything from the
> mailinglist threads, since several commit messages have been infected
> with typos, and they got fixed without a new patch version.
>
> - Correct the point of no return.
> - Add two new mutexes to replace cred_guard_mutex.
> - Fix each use of cred_guard_mutex.
> - Update documentation.
> - Add a test case.
>
> Bernd Edlinger (11):
>   exec: Fix a deadlock in strace
>   selftests/ptrace: add test cases for dead-locks
>   mm: docs: Fix a comment in process_vm_rw_core
>   kernel: doc: remove outdated comment cred.c
>   kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve
>   proc: Use new infrastructure to fix deadlocks in execve
>   proc: io_accounting: Use new infrastructure to fix deadlocks in execve
>   perf: Use new infrastructure to fix deadlocks in execve
>   pidfd: Use new infrastructure to fix deadlocks in execve
>   exec: Fix dead-lock in de_thread with ptrace_attach
>   doc: Update documentation of ->exec_*_mutex
>
> Eric W. Biederman (5):
>   exec: Only compute current once in flush_old_exec
>   exec: Factor unshare_sighand out of de_thread and call it separately
>   exec: Move cleanup of posix timers on exec out of de_thread
>   exec: Move exec_mmap right after de_thread in flush_old_exec
>   exec: Add exec_update_mutex to replace cred_guard_mutex
>
>  Documentation/security/credentials.rst    |  29 +++++--
>  fs/exec.c                                 | 122 ++++++++++++++++++++++--------
>  fs/proc/base.c                            |  23 +++---
>  include/linux/binfmts.h                   |   8 +-
>  include/linux/sched/signal.h              |  17 ++++-
>  init/init_task.c                          |   3 +-
>  kernel/cred.c                             |   4 +-
>  kernel/events/core.c                      |  12 +--
>  kernel/fork.c                             |   7 +-
>  kernel/kcmp.c                             |   8 +-
>  kernel/pid.c                              |   4 +-
>  kernel/ptrace.c                           |  20 ++++-
>  kernel/seccomp.c                          |  15 ++--
>  mm/process_vm_access.c                    |   2 +-
>  tools/testing/selftests/ptrace/Makefile   |   4 +-
>  tools/testing/selftests/ptrace/vmaccess.c |  86 +++++++++++++++++++++
>  16 files changed, 278 insertions(+), 86 deletions(-)
>  create mode 100644 tools/testing/selftests/ptrace/vmaccess.c

Two small nits.

- You reposted my patches with adding your signed-off-by
- You reposted my patches and did not include a "From:"
  in the body so "git am" listed you as the author.

I have fixed those up and will be merging this code to linux-next,
unless you object.

Eric