From: Nam Cao namcao@linutronix.de

When rv_is_container_monitor() is called on the last monitor in rv_monitors_list, KASAN yells:

BUG: KASAN: global-out-of-bounds in rv_is_container_monitor+0x101/0x110 Read of size 8 at addr ffffffff97c7c798 by task setup/221

The buggy address belongs to the variable: rv_monitors_list+0x18/0x40

This is due to list_next_entry() is called on the last entry in the list. It wraps around to the first list_head, and the first list_head is not embedded in struct rv_monitor_def.

Fix it by checking if the monitor is last in the list.

Cc: stable@vger.kernel.org Cc: Gabriele Monaco gmonaco@redhat.com Fixes: cb85c660fcd4 ("rv: Add option for nested monitors and include sched") Link: https://lore.kernel.org/e85b5eeb7228bfc23b8d7d4ab5411472c54ae91b.1744355018.... Signed-off-by: Nam Cao namcao@linutronix.de Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org --- kernel/trace/rv/rv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/rv/rv.c b/kernel/trace/rv/rv.c index 968c5c3b0246..e4077500a91d 100644 --- a/kernel/trace/rv/rv.c +++ b/kernel/trace/rv/rv.c @@ -225,7 +225,12 @@ bool rv_is_nested_monitor(struct rv_monitor_def *mdef) */ bool rv_is_container_monitor(struct rv_monitor_def *mdef) { - struct rv_monitor_def *next = list_next_entry(mdef, list); + struct rv_monitor_def *next; + + if (list_is_last(&mdef->list, &rv_monitors_list)) + return false; + + next = list_next_entry(mdef, list);

return next->parent == mdef->monitor || !mdef->monitor->enable; }