Messages in this thread | | | Date | Tue, 6 Apr 2021 08:27:26 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] ftrace: Check if pages were allocated before calling free_pages() |
| |
On Tue, 6 Apr 2021 14:51:45 +0800 Jiapeng Chong <jiapeng.chong@linux.alibaba.com> wrote:
> It is possible that on error pg->size can be zero when getting its > order,which would return a -1 value. It is dangerous to pass in an > order of -1 to free_pages(). Check if order is greater than or equal > to zero before calling free_pages(). > > Reported-by: Abaci Robot <abaci@linux.alibaba.com> > Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> > --- > kernel/trace/ftrace.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index b7e29db..74efc33 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -6811,7 +6811,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) > if (!pg->index) { > *last_pg = pg->next; > order = get_count_order(pg->size / ENTRIES_PER_PAGE); > - free_pages((unsigned long)pg->records, order); > + if (order >= 0) > + free_pages((unsigned long)pg->records, order);
This has already been fixed upstream.
-- Steve
> ftrace_number_of_pages -= 1 << order; > ftrace_number_of_groups--; > kfree(pg);
| |