From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792594242; b=0MyJwXmANKTTTHkfdvCnhN4UgUYc9/zLX5kmkeIRoJBmwW8xiMfeOtZLEsmmq8kodfEi SgAV/DwSH6YEghGvXUPcbsk9QLKEtmSW4i8d5m1mW41ObPuX9wgqvscJVIidJ1YouxQw5 6Rvy+Zr7v3VrsZU9UaTbB7IjZbnWChwnOyVbTR2BrvNWaEKFrHzblfoMiLSUx3zXkSyhw qullx1ljmRZby0jB2qZanuayeRd16dQ4iDWmfokkwCoOQet/a6V/8dSemMDYe+XIIn2Zf wSQ/BsCgdKHaYN6jIWtUpEVJ9RJ+npcQz01PhNnpNl3n7hlw9fnCis2RcAFRabEluIg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792594242; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=bY1zRcbVSEN2JsAefOMNKbciI0zqhuwOD2i5pwIWulI=; b=oZxGJtJXDW3Qx7EAQ6mYSnixroD1ShQovwmOvHBDP1IaCg6RQHxC2K08bqCokG8+TWWO 8iaaQlpMRPRDxSAI/08BdqFnXWWmKpxvCksdBkfNTZTOcZN9UsvnL3dVRXQLS6KHpBuUi oE6YnXh8ICULVVRkcVTtRPapFC0LFdOCC+Fjg1i3KMlf6ubXnj41w+QSX+FJg+GpD7UZM GRJXqDAvpbevASV9dyU6K5HofidFBra56YK1HsKjZxp4RU0KdXTJE7t9VvHr5hqgES+ad 7epxcg1qCPRhjgbUkPwGqNN2aGlaw92Y8sJJGIZ/e7KElshry+mE/IdEMyUd3WEpgeQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=BMlH767W; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E08A606A31B for ; Wed, 21 Oct 2026 14:50:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=BMlH767W Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A6531F000C1; Wed, 21 Oct 2026 14:50:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792594241; bh=bY1zRcbVSEN2JsAefOMNKbciI0zqhuwOD2i5pwIWulI=; h=Subject:To:Cc:From:Date; b=BMlH767WhwWn1pHMlVnTWrQEvF+hunT5O/6dq1u0OpWXwxzImAg/4FmofUceDo3kH HZ1yMW7q1bhTJbVjB5rRJ4wi6RGaQVwR28H6LO7Q7pqbDQWmdhDE6hwb7FDraApMNI 2F3aOEz0NGLKyhW+W9yb0u0EZuxIkgsdBXNecRB8= Subject: FAILED: patch "[PATCH] tracing/histograms: Reject non-stacktrace fields for" failed to apply to 5.15-stable tree To: lee@kernel.org,mhiramat@kernel.org,rostedt@goodmis.org Cc: From: Date: Wed, 21 Oct 2026 16:42:26 +0200 Message-ID: <2026102126-gallantly-unknotted-4bc4@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x a244c241593b5b38a08f0df2cb43c26574efbdcb # git commit -s git send-email --to '' --in-reply-to '2026102126-gallantly-unknotted-4bc4@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a244c241593b5b38a08f0df2cb43c26574efbdcb Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Tue, 13 Oct 2026 11:24:48 +0000 Subject: [PATCH] tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields 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 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;