[0/6] kernel: Avoid memcpy of task comm

Message

Yafang Shao June 2, 2024, 2:37 a.m. UTC

Using memcpy to copy the task comm relies on the length of task comm.
Changes in the task comm could result in a destination string that is not
NUL-terminated. Therefore, we should explicitly ensure the destination
string is always NUL-terminated, regardless of the task comm. This approach
will facilitate future extensions to the task comm.

As suggested by Linus [0], we can identify all relevant code with the
following git grep command:

  git grep 'memcpy.*->comm\>'

Suggested-by: Linus Torvalds <[e-mail]>
Link: https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=[e-mail]/ [0]

Yafang Shao (6):
  fs/exec: Drop task_lock() inside __get_task_comm()
  tracing: Replace memcpy() with __get_task_comm()
  auditsc: Replace memcpy() with __get_task_comm()
  security: Replace memcpy() with __get_task_comm()
  bpftool: Make task comm always be NUL-terminated
  selftests/bpf: Replace memcpy() with __get_task_comm()

 fs/exec.c                                     |  7 +++--
 include/linux/sched.h                         |  2 +-
 include/linux/tracepoint.h                    |  4 +--
 include/trace/events/block.h                  | 10 +++----
 include/trace/events/oom.h                    |  2 +-
 include/trace/events/osnoise.h                |  2 +-
 include/trace/events/sched.h                  | 27 ++++++++++---------
 include/trace/events/signal.h                 |  2 +-
 include/trace/events/task.h                   |  4 +--
 kernel/auditsc.c                              |  6 ++---
 security/lsm_audit.c                          |  4 +--
 security/selinux/selinuxfs.c                  |  2 +-
 tools/bpf/bpftool/pids.c                      |  2 ++
 .../bpf/bpf_testmod/bpf_testmod-events.h      |  2 +-
 14 files changed, 41 insertions(+), 35 deletions(-)