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=1793024573; b=QFN59yDt+t17o3QMjPov3ZVp1qY8/2/gooLczdCXyjUnCuY5JmEEwfhO0nIMJGsa9Xqe bXiqr/98Zcv6ehKJAlGZ5N5PrqTVecEZxDkagG65huv8ik9dAfa8+skEJkm5yeuCO4Mgd YhyJ09e4fRysb1LHv186GkKydNoS4kXC4KO26hZS3lM/7+sLzk9au2JFxpdwCT2VCrCp/ aW2cGood+XjTnP9JXVDUr2KdqJvqWmKQNLBdC/XUPlZet2F4osiRV6xNosuQKlds4ViPn ssGKKa2+XxqMl/BU9iKvu8BnTrfvL46Wq6uiI2iRhvWmd7YQOR+oRv1fuwitbeInyfg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793024573; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Transfer-Encoding; bh=1UtlG/I50/AGyhCzapfCShuG8oAfU+hAtrPZyA2cTAU=; b=wuc5N/+84QTtu09w5gaOFKEHaaG8MF0ywFr9cNDIC9NknQp/zIJL04VMwHUkhfnoQHbd AKnnudjYNr8CgsqeTv1ucnu4wx4977NXR3siZaSwLkmmOgwwwSewOQ3wVPVHV6U+/y0Nc drBve/WHxf8T9kJO6DM5cECsP5pg9taNDrGdc960WWDIwPKE5CxM/ZWg7TYvpLmhXxVho dTSAFbEbVSY9FAPc3m3AI7wruvwpRalZP3wAtWWRJrjJ+Z4OJ6YcJ8Ivma6JPsRt9yuk1 mDyRFFot0SDWkgNCzfghD/peITSPc6cMORfdlWN5wI82M6n+PHGw7EfLcATI0xPAkpg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=iCUcS+7P; 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 01266606A326; Mon, 26 Oct 2026 14:22:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=iCUcS+7P Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F9F31F01828; Mon, 26 Oct 2026 14:22:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793024572; bh=1UtlG/I50/AGyhCzapfCShuG8oAfU+hAtrPZyA2cTAU=; h=From:To:Cc:Subject:Date; b=iCUcS+7P9f6/HxtuTfZcbpU43fdlBII3hHFl77wd+3Q1E+bUnhF1WLwvbDaqyJVtO F2rg4dushI4Qdqry2wT69iw+NHWJMB5MSPy4H9ldS+zuGMxW7JMNEFLBtSjKptidM+ q+9bZ/aJ1BiEAwMoznAY2kwLuqPdiuMAxxOi5RSxTUClLQetNLIw5Rd5OHs4LqZbHL CKWsBg8fVkO9ycnnpZ5S1hxyhxy3k9oSsNWwK3DzkBB6v7tpIH65cNsW8WmMInYLMG jr8Lkhfu4/4DCR1UCIuKVnMGE+4HZRx/wBrOkE64I7gfRRoTZk15j1orHWTTNNOr6N Opl3xIx2DSczw== From: Lee Jones To: lee@kernel.org, Steven Rostedt , Masami Hiramatsu , Tom Zanussi , linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Subject: [STABLE v6.1-v5.10] tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields Date: Mon, 26 Oct 2026 14:22:47 +0000 Message-ID: <20261026142248.3526008-1-lee@kernel.org> X-Mailer: git-send-email 2.56.0.257.gf7497c7d27-goog X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit [ Upstream commit a244c241593b5b38a08f0df2cb43c26574efbdcb ] 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 [Lee: Omit create_var_field() and hist_trigger_elt_update() hunks as 288709c9f3b0 ("tracing: Allow stacktraces to be saved as histogram variables") is not present] Signed-off-by: Lee Jones --- kernel/trace/trace_events_hist.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 8e5efdfa0fc7..b8fb45fa3cfc 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2066,7 +2066,8 @@ 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); @@ -3203,6 +3204,7 @@ static struct field_var *create_field_var(struct hist_trigger_data *hist_data, ret = -ENOMEM; goto err; } + var->flags |= val->flags & HIST_FIELD_FL_STACKTRACE; field_var->var = var; field_var->val = val; @@ -3820,7 +3822,10 @@ 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) { -- 2.56.0.257.gf7497c7d27-goog