From 803aa6fc2dbea25ab9d3ed19eca1c96d0ab17445 Mon Sep 17 00:00:00 2001 From: Taeyang Lee <0wn@theori.io> Date: Fri, 16 Oct 2026 02:19:05 +0900 Subject: [PATCH] tracing: Keep the predicate limit separate from program capacity predicate_parse() adds two to nr_preds to reserve the terminal TRUE and FALSE entries. It also uses that increased value as the limit for parsed predicates. If the initial count is smaller than the number actually parsed, the program can fill the allocation and subsequent accesses can go past its end. Keep nr_preds as the predicate limit and use a separate value for the allocation size. This leaves space for both terminal entries and a zeroed entry when parsing stops at the limit. Cc: stable@vger.kernel.org Fixes: 39f7c41c908b ("tracing/filters: Enable filtering a cpumask field by another cpumask") Link: https://patch.msgid.link/atELCd1XjKVhrkFL@Taeyangs-MacBook-Pro.local Signed-off-by: Taeyang Lee <0wn@theori.io> Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_filter.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 2b46ca536045..781416ba6bdf 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -482,18 +482,17 @@ predicate_parse(const char *str, int nr_parens, int nr_preds, int len; int N = 0; int i; - - nr_preds += 2; /* For TRUE and FALSE */ + int nr_preds_alloc = nr_preds + 2; /* For TRUE and FALSE */ op_stack = kmalloc_objs(*op_stack, nr_parens); if (!op_stack) return ERR_PTR(-ENOMEM); - prog_stack = kzalloc_objs(*prog_stack, nr_preds); + prog_stack = kzalloc_objs(*prog_stack, nr_preds_alloc); if (!prog_stack) { parse_error(pe, -ENOMEM, 0); goto out_free; } - inverts = kmalloc_array(nr_preds, sizeof(*inverts), GFP_KERNEL); + inverts = kmalloc_array(nr_preds_alloc, sizeof(*inverts), GFP_KERNEL); if (!inverts) { parse_error(pe, -ENOMEM, 0); goto out_free;