Re: [PATCH 1/2] ftrace: Fix NULL pointer dereference in t_probe_next()

[Naveen N. Rao]

Steven Rostedt wrote:

On Thu,  4 Jul 2019 20:04:41 +0530
"Naveen N. Rao" <naveen.n....@linux.vnet.ibm.com> wrote:

 kernel/trace/ftrace.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7b037295a1f1..0791eafb693d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3093,6 +3093,10 @@ t_probe_next(struct seq_file *m, loff_t *pos)
                hnd = &iter->probe_entry->hlist;

hash = iter->probe->ops.func_hash->filter_hash;

+
+       if (!hash)
+               return NULL;
+
        size = 1 << hash->size_bits;

retry:

OK, I added this, but I'm also adding this on top:

Thanks, the additional comments do make this much clearer.

Regards,
Naveen