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 318D547986B for ; Thu, 10 Sep 2026 11:46:49 +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=1789040812; cv=none; b=CD6pAb2H/YW0VzSTDfnGi6muairj6pSDUytC/ibOQcWaYZ81M6aWf7EOr5pUsB5w+NSO7AIsWDw0wOLMCGvutdSx/iM/6R8q/jd/aEUCGmmj8/jq6lb2JYUokn/Qo0qs1ilr9KXoqOl/Cmmjor1TplFUg7nvr9AlXF6Gh+4EEc4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789040812; c=relaxed/simple; bh=F6lohWUYc2QNMuIHc/MWOd0fU5LKPXL3/YoO6V/UA94=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Y7Kkp9C4Vch0iC5w5l1LOlZ8+32LkiBsuYyF/B22Wr5VbuUL5VX4tWYu5GZ9Q5/m4bcFHqQaFAq5WTodVqtAY7msSbs1UU0+1UdUeUsmWRk4yJZMG7nbx7ZsGyok+mvu83gaBlxgOvtrkrKHaSQcTJlUbNjbsXP1wtKNMAT6ORg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j32vg+/i; 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="j32vg+/i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D6C11F000FF; Thu, 10 Sep 2026 11:46:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789040807; bh=KUB5e1oZPv+hl7t1ZEc3bPZ35WbuSPcniF5D8IqsfbE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=j32vg+/i7zHJM2OEt0IMxsV0fzrJs1N6MZGr6iXXAmM8Iv2EuPe9NUkG24xOQ6o8J ydOjFNnDbIPy9vu8Bwl0UTzT26U+pLEe7M8FDuX6vWapv/R90nhhdcPUzX2ltRnCaK hGQtzdxMuOfzpy2RAOmQcL8O85dAmQkkxPeXFdRzqqWL84jKzCChD8s+rsLzzfcQ9Y 5zg+VLz615Lns3SXO8N2FbsWapflsLmZWXBlWF8vzi5A2I9n2zKzcuXFODZBvsi2DM vX2bcepoJQcnRvovXh5xAH1tEvmrCGGjjG3qsIg2STlA6F32fD2Z9YCoo+n6ZDCPgn niSDcD7XcpTIA== From: Sasha Levin To: stable@vger.kernel.org Cc: "Masami Hiramatsu (Google)" , Sashiko , Steven Rostedt , Sasha Levin Subject: [PATCH 6.6.y] tracing/probes: Fix anon_stack check for unnamed bitfields in btf_find_struct_member Date: Thu, 10 Sep 2026 07:46:45 -0400 Message-ID: <20260910114645.98172-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026090811-scone-shakiness-7ec5@gregkh> References: <2026090811-scone-shakiness-7ec5@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: "Masami Hiramatsu (Google)" [ Upstream commit f36d94a20ca185bcadef3a10b980cd2cfd72d53a ] btf_find_struct_member() traverses into nested anonymous structures and unions by pushing members with !member->name_off onto anon_stack. However, it does not consider the unnamed bitfields (e.g. `int : 5` or `unsigned int : 0`) which also have member->name_off == 0. If such an unnamed bitfield is pushed to anon_stack, the btf_find_struct_member() return an error even if there are other valid entries in anon_stack. To fix this, only push unnamed struct/union members to anon_stack. Also move the btf_type_is_struct() check to the entry of this function because now it is sure only struct/union are pushed to anon_stack. Link: https://lore.kernel.org/all/178827249775.123716.7813217688423513612.stgit@devnote2/ Fixes: 302db0f5b3d8 ("tracing/probes: Add a function to search a member of a struct/union") Cc: stable@vger.kernel.org Reported-by: Sashiko Closes: https://lore.kernel.org/all/20260830143859.D56991F00A3D@smtp.kernel.org/ Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt [ retained the existing kcalloc() allocation instead of upstream’s kzalloc_objs() call. ] Signed-off-by: Sasha Levin --- kernel/trace/trace_btf.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_btf.c b/kernel/trace/trace_btf.c index 5bbdbcbbde3cd..40e66eb59abbc 100644 --- a/kernel/trace/trace_btf.c +++ b/kernel/trace/trace_btf.c @@ -74,24 +74,24 @@ const struct btf_member *btf_find_struct_member(struct btf *btf, { struct btf_anon_stack *anon_stack; const struct btf_member *member; + const struct btf_type *mtype; u32 tid, cur_offset = 0; const char *name; int i, top = 0; + if (!btf_type_is_struct(type)) + return ERR_PTR(-EINVAL); + anon_stack = kcalloc(BTF_ANON_STACK_MAX, sizeof(*anon_stack), GFP_KERNEL); if (!anon_stack) return ERR_PTR(-ENOMEM); retry: - if (!btf_type_is_struct(type)) { - member = ERR_PTR(-EINVAL); - goto out; - } - for_each_member(i, type, member) { if (!member->name_off) { /* Anonymous union/struct: push it for later use */ - if (btf_type_skip_modifiers(btf, member->type, &tid) && + mtype = btf_type_skip_modifiers(btf, member->type, &tid); + if (mtype && btf_type_is_struct(mtype) && top < BTF_ANON_STACK_MAX) { anon_stack[top].tid = tid; anon_stack[top++].offset = -- 2.53.0