Message ID | 20240327174747.612002-1-kiryushin@ancud.ru (mailing list archive) |
---|---|
State | Accepted |
Commit | cb85f6247a6e1cbb10536eb5ae7055de07051944 |
Headers | show |
Series | [v4] rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow | expand |
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> -- 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),
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), >
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),
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(). 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(-)