Messages in this thread | | | Date | Wed, 27 Mar 2024 11:31:01 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH v4] rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow |
| |
On Wed, Mar 27, 2024 at 01:52:46PM -0400, Steven Rostedt wrote: > On Wed, 27 Mar 2024 20:47:47 +0300 > Nikita Kiryushin <kiryushin@ancud.ru> wrote: > > > There is a possibility of buffer overflow in > > show_rcu_tasks_trace_gp_kthread() if counters, passed > > to sprintf() are huge. Counter numbers, needed for this > > are unrealistically high, but buffer overflow is still > > possible. > > > > Use snprintf() with buffer size instead of sprintf(). > > > > Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Queued and pushed, thank you both!
Thanx, Paul
> -- Steve > > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > > > Fixes: edf3775f0ad6 ("rcu-tasks: Add count for idle tasks on offline CPUs") > > Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru> > > --- > > v4: Change ARRAY_SIZE to sizeof() as more idiomatic > > as Steven Rostedt <rostedt@goodmis.org> suggested > > v3: Fixed commit message > > v2: Use snprintf() as > > Steven Rostedt <rostedt@goodmis.org> suggested. > > kernel/rcu/tasks.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h > > index 147b5945d67a..2a453de9f3d9 100644 > > --- a/kernel/rcu/tasks.h > > +++ b/kernel/rcu/tasks.h > > @@ -1994,7 +1994,7 @@ void show_rcu_tasks_trace_gp_kthread(void) > > { > > char buf[64]; > > > > - sprintf(buf, "N%lu h:%lu/%lu/%lu", > > + snprintf(buf, sizeof(buf), "N%lu h:%lu/%lu/%lu", > > data_race(n_trc_holdouts), > > data_race(n_heavy_reader_ofl_updates), > > data_race(n_heavy_reader_updates), >
| |