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=1793210105; b=RHYxhOKvwZSY8TWAA43yhTzOQvqHVWxGEdBZX9PNrmxqOJogWnFyrRViXHLOicxr+vJU JUcmDmnoOd/3S0QxapCRnudgy2KIuuRx3V5YT9Jd0XcSyyKxvjXjSmfOPw16evUBvaGOF jyfGRIgNmeNzad9B6GxuQu2kRDbcQSTmMmDtC1T5/dpYFFElylUvduB+j4aHNHS6W/9I7 wfqHBsL39VYR27UX4DLObSJdDohpNLvJi90Wl4Vyv8geKrbC8P5z5rEGZ9suAmFzztp1p +zguWq8ifMdD3I/G0Ti5XCIf5JSqiyYqWOcmENeLsKxEQGjKa9rXklAsiAVnh8fcvwA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210105; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=OG991RQMkyMnZUrkVZFm+ArAT+fACVCoKMbyRjpidmU=; b=FYLp6FEIxNZRPghGP/bHeg1tVs525sYNTn0FkICpjHtBdt7/iSs8KZAEX37oR/TXwikI SNI/Ljn72ykKzB70/qoqtTfSo8DX4yNubRnw/licDIE1iZWGLky40qPDMVO6qU7Wb0yWN WJqBUHGKKismvM8un/TfxAleis6eDWa4qSwKt9LNeBZx93lwfupeKWvSBwSaziBWFnW49 xZt6w1w0R5st+4mHklDpHO4e66jDJTs9OxLCLIFpd4P5j2ubRY6YjCkwUIKU7iSrFHTXw 0ZazjG4aBSwt0v3semi01LknSc1XYRFkfPsF6RYGShkKUH9Mjs+SRg40fV0+AXTDTgQ== 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=s2GKgKqG; 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 2DA2C606A321; Wed, 28 Oct 2026 17:55:05 +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=s2GKgKqG Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E4091F01825; Wed, 28 Oct 2026 17:55:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210105; bh=OG991RQMkyMnZUrkVZFm+ArAT+fACVCoKMbyRjpidmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=s2GKgKqGjoa8AD88EeC11X1DhMm6gfD6v/KGkeqELuHdN3L3r5y4dV5iOz6RdUqMH Mi6sbdOFFKhMddvkEfTzV/S6aOl6ANK/+GWRFWsypol8qLso5fj3popz3d8INjdoR0 Jo7ksl030UdF12GxFzBEqfVwlpeOvwz+ru/gbL3M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lee Jones , "Masami Hiramatsu (Google)" , Steven Rostedt Subject: [PATCH 6.6 051/168] tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields Date: Wed, 28 Oct 2026 17:59:47 +0100 Message-ID: <20261028165944.297482113@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028165943.089486480@linuxfoundation.org> References: <20261028165943.089486480@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lee Jones commit a244c241593b5b38a08f0df2cb43c26574efbdcb upstream. 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 Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events_hist.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2098,7 +2098,8 @@ static int init_var_ref(struct hist_fiel 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); @@ -3286,6 +3287,7 @@ static struct field_var *create_field_va ret = -ENOMEM; goto err; } + var->flags |= val->flags & HIST_FIELD_FL_STACKTRACE; field_var->var = var; field_var->val = val; @@ -3904,7 +3906,10 @@ static int check_synth_field(struct synt && 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) { @@ -4443,7 +4448,8 @@ static int create_var_field(struct hist_ 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++; @@ -5185,7 +5191,8 @@ static void hist_trigger_elt_update(stru 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;