From 227a8748742f0263f1fe3131449b44563b77a209 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Sun, 7 Jun 2026 14:35:28 -0300 Subject: [PATCH] perf hists: Fix snprintf() in hists__scnprintf_title() UID filter path hists__scnprintf_title() accumulates formatted output into a buffer using scnprintf() for all filter clauses except the UID filter, which uses snprintf(). If the buffer fills up and snprintf() returns more than the remaining space, printed exceeds size and the next 'size - printed' underflows, causing later scnprintf() calls to write past the buffer. Switch the UID filter clause to scnprintf() to match the rest of the function. Fixes: 25c312dbf88ca402 ("perf hists: Move hists__scnprintf_title() away from the TUI code") Reported-by: sashiko-bot Reviewed-by: Ian Rogers Cc: Arnaldo Carvalho de Melo Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/hist.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c index 811d68fa6770..df978c996b6c 100644 --- a/tools/perf/util/hist.c +++ b/tools/perf/util/hist.c @@ -2963,9 +2963,10 @@ int __hists__scnprintf_title(struct hists *hists, char *bf, size_t size, bool sh ev_name, sample_freq_str, enable_ref ? ref : " ", nr_events); - if (hists->uid_filter_str) - printed += snprintf(bf + printed, size - printed, - ", UID: %s", hists->uid_filter_str); + if (hists->uid_filter_str) { + printed += scnprintf(bf + printed, size - printed, + ", UID: %s", hists->uid_filter_str); + } if (thread) { if (hists__has(hists, thread)) { printed += scnprintf(bf + printed, size - printed,