From 10b3c3d63ecc17c6acb855bac5f40367f1115765 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 10 Jun 2026 21:01:15 -0300 Subject: [PATCH] perf bpf: Validate func_info_rec_size and sub_id in synthesize_bpf_prog_name() synthesize_bpf_prog_name() computes a pointer into the func_info array using sub_id * info->func_info_rec_size without validating either value. Both come from perf.data and are untrusted: - A func_info_rec_size smaller than sizeof(struct bpf_func_info) means the finfo pointer would reference a truncated entry, reading past it into adjacent data. - A sub_id >= nr_func_info computes an offset past the func_info buffer, causing an out-of-bounds read. Add bounds checks for both values before computing the pointer offset. When validation fails, fall through to the non-BTF name path instead of reading garbage. Reported-by: sashiko-bot Fixes: 7b612e291a5affb1 ("perf tools: Synthesize PERF_RECORD_* for loaded BPF programs") Cc: Song Liu Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/bpf-event.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index c4594969d767..fe6fbca508c5 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -143,7 +143,9 @@ static int synthesize_bpf_prog_name(char *buf, int size, name_len = scnprintf(buf, size, "bpf_prog_"); name_len += snprintf_hex(buf + name_len, size - name_len, prog_tags[sub_id], BPF_TAG_SIZE); - if (btf) { + if (btf && + info->func_info_rec_size >= sizeof(*finfo) && + sub_id < info->nr_func_info) { finfo = func_infos + sub_id * info->func_info_rec_size; t = btf__type_by_id(btf, finfo->type_id); if (t)