On Tue, Oct 26, 2021 at 5:16 AM Kees Cook [off-list ref] wrote:

On Mon, Oct 25, 2021 at 08:33:07AM +0000, Yafang Shao wrote:

quoted

Use strscpy_pad() instead of strlcpy() to make the comm always nul
terminated. As the comment above the hard-coded 16, we can replace it
with TASK_COMM_LEN, then it will adopt to the comm size change.

Signed-off-by: Yafang Shao <redacted>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <redacted>
Cc: Andrii Nakryiko <redacted>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <redacted>
Cc: Petr Mladek <pmladek@suse.com>
---
 drivers/infiniband/hw/qib/qib.h          | 2 +-
 drivers/infiniband/hw/qib/qib_file_ops.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/qib/qib.h b/drivers/infiniband/hw/qib/qib.h
index 9363bccfc6e7..a8e1c30c370f 100644
--- a/drivers/infiniband/hw/qib/qib.h
+++ b/drivers/infiniband/hw/qib/qib.h

@@ -196,7 +196,7 @@ struct qib_ctxtdata {
      pid_t pid;
      pid_t subpid[QLOGIC_IB_MAX_SUBCTXT];
      /* same size as task_struct .comm[], command that opened context */
-     char comm[16];
+     char comm[TASK_COMM_LEN];
      /* pkeys set by this use of this ctxt */
      u16 pkeys[4];
      /* so file ops can get at unit */

diff --git a/drivers/infiniband/hw/qib/qib_file_ops.c b/drivers/infiniband/hw/qib/qib_file_ops.c
index 63854f4b6524..7ab2b448c183 100644
--- a/drivers/infiniband/hw/qib/qib_file_ops.c
+++ b/drivers/infiniband/hw/qib/qib_file_ops.c

@@ -1321,7 +1321,7 @@ static int setup_ctxt(struct qib_pportdata *ppd, int ctxt,
      rcd->tid_pg_list = ptmp;
      rcd->pid = current->pid;
      init_waitqueue_head(&dd->rcd[ctxt]->wait);
-     strlcpy(rcd->comm, current->comm, sizeof(rcd->comm));
+     strscpy_pad(rcd->comm, current->comm, sizeof(rcd->comm));

This should use (the adjusted) get_task_comm() instead of leaving this
open-coded.

Sure, that is better.

quoted

      ctxt_fp(fp) = rcd;
      qib_stats.sps_ctxts++;
      dd->freectxts--;
--
2.17.1

--
Kees Cook

-- 
Thanks
Yafang