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=1794446839; b=Jq7MWbOKZh/UgBgO57oxS0JdzzBIHyRIMzx7SNY3Wglj6Xu/hRjuYNG/bEH5tNAmYEaE wvz9bqbWaKsgN0+QjYt0hy24P9CDWGG777Tv6EAL9kCavRqtRWURikGOT6BYL1oTyJT6o dPyVCUS14JUcfRwddauN76LvZ2Ye8KWlvYm4qonDBgcWkyQgGapHxRIRRKt0rCzHuAZKy T/BHRNrMiNAdgj7ZdSb+bRTJw002Rw4GcVIm5VcxwF2poTYnociuM8r3TydRgetFu76jl O4jJBvmCGcsA/rFU1I3dTs7DXQXWqN0ad+yu78aAEsBrGbJ0FQuCR1EtXT4yknLHydw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794446839; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=eLPKV+XG/NDVIPVGtVsCkLYRyrN/OgHbO9MTpDsW/Zo=; b=p2V2gmQ2/YAwpBHKAu9fWfyXhQMC82SDElAu5GBgzE0+dUCVbaG60XGIEzdK8mdUdril 7f1NsaQ1lx1IJKJKk1ZoFWHpsj48Y13kpglENhYasTZBWLVTXOgHn17F6BOJSqiBfXQEm 1nfGbrbLb0mHcOTe5+ZY47p/pNqkz0DOjexURzvwaC2Mk+TaS8F9wO5nmr+uHfA3rUTQE J6Ds4fgI5Ra9r96yE0bGYtR+ioMG24jQjL/YCqNDSMM0J9yTzMtb6tngpaGcgAhhXIn1/ szxWtsJLlDYV0rJvx16S968yOsvSEImnsPTL8IRFowJ58YszPB1+bWrsfhL1x6SXrAw== 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=X1ObL4vM; 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 A3AA6606A321; Thu, 12 Nov 2026 01:27:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=X1ObL4vM Received: by smtp.kernel.org (Postfix) with ESMTPSA id 104CF1F00A05; Thu, 12 Nov 2026 01:27:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794446839; bh=eLPKV+XG/NDVIPVGtVsCkLYRyrN/OgHbO9MTpDsW/Zo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=X1ObL4vMedeEeMQHtzNiIiZR8ZE417joAJkDIKoV5+9V0WUJE5p4vkBeavzZEABiW 8LCs0SFyBrlPFQ+mrBEzHJd2bbkZXi+qQ/SzhrQXlXFtD2/VFX+W9DFq4JRted0vRy KNMEfadnDd0r9cgO/sQoEya3/+O4n1/Yt3Kjy5ArTWoPstQ4PHEI6UATj6qlwE+aAy QV0vacGHmZZbQqICUX98r9HGh/9LjHuhovjRCL7UQnD5y5azZ8XPGWTUHgeqngYmvx Kb1AMKGvf3UAxsly8jzM/Hi3nXrHUzrrlfuyDjPfsMhfVpN9cEGuqrAPhmKDPMhFQt rGjNPM/MJCoFA== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Masami Hiramatsu Cc: Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH v2 04/13] tracing/probes: Fix missing BTF kind checks in char pointer/array helpers Date: Thu, 12 Nov 2026 10:27:15 +0900 Message-ID: <179444683590.345731.13726797901135918302.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <179444679892.345731.5271591537517106679.stgit@devnote2> References: <179444679892.345731.5271591537517106679.stgit@devnote2> User-Agent: StGit/0.19 X-Mailing-List: linux-trace-kernel@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="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) In struct btf_type, the type ID and byte size share a union, and only BTF_KIND_INT types are followed by a 32-bit integer encoding word. Because btf_type_is_char_ptr() and btf_type_is_char_array() do not verify that the outer type is BTF_KIND_PTR or that the resolved element type is a non-NULL BTF_KIND_INT before inspecting it, non-pointer BTF types can have their byte size misinterpreted as a BTF type ID, and arrays of non-integer types read out-of-bounds or misinterpret trailing BTF metadata as BTF_INT_* encoding bits. Validate the BTF type kinds and NULL pointers before reading inner type metadata in both helpers. Fixes: 27973e5c64b9 ("tracing/probes: Add string type check with BTF") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_probe.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 3a57fe6b67cc..232d1deecb20 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -411,6 +411,9 @@ static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type) const struct btf_type *real_type; u32 intdata; + if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) + return false; + real_type = btf_type_skip_modifiers(btf, type->type, NULL); if (!real_type) return false; @@ -435,6 +438,11 @@ static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type) array = (const struct btf_array *)(type + 1); real_type = btf_type_skip_modifiers(btf, array->type, NULL); + if (!real_type) + return false; + + if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT) + return false; intdata = btf_type_int(real_type); return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)