From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3222352CCED; Thu, 15 Oct 2026 13:34:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792071248; cv=none; b=LZ5/+SKdVcvurqpTtPN9+vQlnG9iAHZ/IYQhQq4Ci2pElNqT3FMP94pN/WAu6rCRqS6QnNxlQPJHZi9SZyJlMDbDTZ8FhPJoj0uSu9ZjCStUY10D7OkMc3J+TkPy3feEyBaNCdvpsyr1AW2PC/Hb0NVd3/QprXXHS4SjPSbp3xs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792071248; c=relaxed/simple; bh=kRA7wR0Lu2ILqY7s+P4GH6XQ2xOocIz2J3AnBq61uso=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=OVHB9Ot63fOx+VzyYyKpDJX7iUvAKHRpED1ARCVHQDi1PQgmJBT+rd4Ph/QkmB1V+cj4x5tcKYAEi5iCeS506/zkToYrzMvBenOnASY4XMyKq/gK5lTSrVpJLPHHYqmP4jTY3oPej4BTl2sgcUw46UF9RNYOHEn8EfcmcfjUTzc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k9izgXze; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k9izgXze" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C3A71F000CA; Thu, 15 Oct 2026 13:34:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792071246; bh=NmjlTVpki8ZFzqxPcRkdL0IDLG9OBVvlQVOnJ2jaiKU=; h=Date:From:To:Cc:Subject:References; b=k9izgXze0WODA2AWq0ZOiTjAk40aoWkEstHUAHjr4UE46+qiCy6pxcwgJrAZfhvft cecmm2nkofIPYXlrnp35FsY7PLsCL+pw9Ixtz6Swcz1bV54gaTUjlbvOJvCD1zIMxk j6U5uR55LLz2HILJP1mjitFZPx2Z2v9hAhBoNnyXETJ4Xcrb5vF5TKegO4USEPlaL5 qPpJ0K5WLMLxGUSq424X015I0/McSiRUfLz1UjtLzvtH4+rF1/CLh2AScKh0YaIl1r 0G62Li0zQdaW0Ios/D8KDz+dAcTDK4DJs0UR0WjHB0nLI4entm9d2S0JlJcOjFr6qm zXfJR1E9dLyhg== Received: from rostedt by gandalf with local (Exim 4.100.1) (envelope-from ) id 1xHLav-00000000MiN-1Lnh; Thu, 15 Oct 2026 09:34:05 -0400 Message-ID: <20261015133405.152631018@kernel.org> User-Agent: quilt/0.69 Date: Thu, 15 Oct 2026 09:33:26 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org, Lee Jones Subject: [for-linus][PATCH 16/16] tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields References: <20261015133310.731003448@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Lee Jones In check_synth_field(), when a synthetic event field is a stacktrace (field->is_stack) and the histogram field is not a "long[" stacktrace array, validation falls through to the generic size and signedness comparison. Because parse_synth_field() sets a stacktrace field's type to "__data_loc unsigned long[]", its size is sizeof(u64) and synth_field_signed() marks it as signed. Consequently, any 8-byte signed scalar histogram field passes the fallback check, and its scalar value is subsequently dereferenced as a kernel stacktrace pointer in get_field_size() and trace_stack(). Furthermore, checking strstr(hist_field->type, "long[") is insufficient because tracepoint fields defined with __bitmask() or __rel_bitmask() also have type "__data_loc unsigned long[]" or "__rel_loc unsigned long[]", whilst create_hist_field() treats them as 4-byte scalar values without HIST_FIELD_FL_STACKTRACE. Propagate HIST_FIELD_FL_STACKTRACE to variable references and field variables (whilst excluding variable aliases from per-element stacktrace capture), and reject any mismatch between HIST_FIELD_FL_STACKTRACE and field->is_stack in check_synth_field(). Cc: stable@vger.kernel.org Fixes: 00cf3d672a9d ("tracing: Allow synthetic events to pass around stacktraces") Link: https://patch.msgid.link/20261013112449.1006088-1-lee@kernel.org Signed-off-by: Lee Jones Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_hist.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 571a57e0f369..dcb5d7321095 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2121,7 +2121,8 @@ static int init_var_ref(struct hist_field *ref_field, ref_field->size = var_field->size; ref_field->is_signed = var_field->is_signed; ref_field->flags |= var_field->flags & - (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); + (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS | + HIST_FIELD_FL_STACKTRACE); if (system) { ref_field->system = kstrdup(system, GFP_KERNEL); @@ -3318,6 +3319,7 @@ static struct field_var *create_field_var(struct hist_trigger_data *hist_data, ret = PTR_ERR(var); goto err; } + var->flags |= val->flags & HIST_FIELD_FL_STACKTRACE; field_var = kzalloc_obj(struct field_var); if (!field_var) { @@ -3946,7 +3948,10 @@ static int check_synth_field(struct synth_event *event, && field->is_dynamic) return 0; - if (strstr(hist_field->type, "long[") && field->is_stack) + if (!!(hist_field->flags & HIST_FIELD_FL_STACKTRACE) != field->is_stack) + return -EINVAL; + + if (field->is_stack) return 0; if (strcmp(field->type, hist_field->type) != 0) { @@ -4487,7 +4492,8 @@ static int create_var_field(struct hist_trigger_data *hist_data, if (!ret && hist_data->fields[val_idx]->flags & HIST_FIELD_FL_EXECNAME) update_var_execname(hist_data->fields[val_idx]); - if (!ret && hist_data->fields[val_idx]->flags & + if (!ret && !(hist_data->fields[val_idx]->flags & HIST_FIELD_FL_ALIAS) && + hist_data->fields[val_idx]->flags & (HIST_FIELD_FL_STRING | HIST_FIELD_FL_STACKTRACE)) hist_data->fields[val_idx]->var_str_idx = hist_data->n_var_str++; @@ -5228,7 +5234,8 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, if (hist_field->flags & HIST_FIELD_FL_VAR) { var_idx = hist_field->var.idx; - if (hist_field->flags & + if (!(hist_field->flags & HIST_FIELD_FL_ALIAS) && + hist_field->flags & (HIST_FIELD_FL_STRING | HIST_FIELD_FL_STACKTRACE)) { unsigned int str_start, var_str_idx, idx; char *str, *val_str; -- 2.53.0