From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f47.google.com (mail-wm1-f47.google.com [209.85.128.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DB2438657D for ; Thu, 20 Aug 2026 15:25:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787239540; cv=none; b=NMIj7K1DqaTGOwmFqAhYr/SqunICj1ZMSZseRmZ37iNUnZvm2ISk2SGOuVxHftCQq+CSirlPB/CX/47hhUE0KAYCUPXf18oxV9HYFxBE+1qtabG8B0Djl6C0IrdKibLXVH3rwik1IEmFDIwqdpZj0srOG+Vcc4u5tTrIF7+95go= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787239540; c=relaxed/simple; bh=ET02yudpTVpDKAfYKMipGbABTJmZB0Fkj/3NMmMn6ts=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=VIuRrGOjTGc71hfcATtQUfbcaGVjsxgBwKDdkvNLxHX/po8HcbB/E1k2+G4gbZNhbLsW55atxTHXPJAmu52qnj/fiGEMJuPNaepT87RcT014bl2HaWcrg3MG8tpc4fwCybgIGOoovzbgUSlbjT8NWA+dZeBJUj757kZpfqGSv9s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=bcHAt0AN; arc=none smtp.client-ip=209.85.128.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bcHAt0AN" Received: by mail-wm1-f47.google.com with SMTP id 5b1f17b1804b1-49954b88fffso25173155e9.0 for ; Thu, 20 Aug 2026 08:25:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1787239537; x=1787844337; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=wwb1+VWDQFtZ7Zc7K8oYCiwpiZ5ICOZorV8IsL6a4vg=; b=bcHAt0ANvlapJyj5UnGWO16uwrCfKMgwh/qoP3dXBrcc7yalItEFne69iRxFkIs2v7 tTBGxsoe6/YY+/0EKUZ2MJeDOE9wXEr41bokkRaxYx1XQHamnaLBdPCHDbk3LXWORmOG AmNmYmdC6TAjPhbFCZggVgfsaeqDmTD1+FlT93aJTra7z/5++BI7wXYYNkn1YTYdFI6m 1BraMHPCqB5pkhNHg8JS/i41Q19ED5mdL8pQNtzp+kofFMKiix+9KNjhhl4yBGm2Fem4 wDO1N+eyAMgXlcWTEA3ysiNw9nIs6y39z2rG0/OGNuYuRZ13a2xiHaJPz8rkwi8Y9b3r C5aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787239537; x=1787844337; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=wwb1+VWDQFtZ7Zc7K8oYCiwpiZ5ICOZorV8IsL6a4vg=; b=ksBoWWMF5HP4YverwgK+fO7vgszz22l76T3R705cfV6Hr03PN1eQVIA9ZEGeBlTSHx Hq+g5gvKbx56lZ1rOAKGblGFZOTrkZEzJbT5FBVrwuH7pBOMGKaZH3RDHEHR/UUycgKV 9DTIxZGXbVuuTy/3WFBPIaGUYgqz/81Z2rm1wal+M7cC18q7pNo0RfkH/UiWQ+vbREFO WDIEcPc2FtexcMNknsHwpRyvkRJ34eVfDhvnRnl6IqKX5h8LZY5UJaWoXwd2IlbmwgH/ lzcwsyjV9FCucS/cYQvGCnqmDCD1OGYXgE0+KmMiaeAQ//ZdhAhdvCeD5LltznHemjlE qR5w== X-Gm-Message-State: AOJu0YwLX6rfjXksw/c9SrasE0PZgOZJkfKlRHCzL0nzDk0Tfe5eO9qs JPf8OxspTy5Os6lPjwScPzehpMtZtFW3wcnrM+gd5leKppbt3wAx2S134ApfjCHUiv8= X-Gm-Gg: AR+sD12CrPiUuYX0gCC67aJ9xWJ+5eRKyiekiqx9+UTH2lti76fy2JOmlCZjs89LaHn bqJE0J88yCjkOergv8JbH1qyW0BF4qDxxzq46CLQ51xGLJ0mm7JJnXIJLNdQffDhTOTX3jXjf/R 8UK5sk0GPias+l/gmkjdDGIVPY69xVQSthzPN0oX/QPlKLbe78C/OlUbOt0iAP7iquKuWaAPD7u I/sX9i5lLmiu6MjGSOs8Y6EUuRHnwfYnPGhEhs21lnbD4p3PkmdCeXIIyIjA2sD0Wgf+vMx9xxQ o/nL9Sm+ICOIJJcPj9ZtfS8kTbpsMn6cpw4R40lpVR5VC1jgJLp/oQBY6e0L6ouYuDkqFoTNprw /tUVpvFPQJqpf6aSs7+7KG6Sm+mKRIl20/9mpB2zkjt/SYgrNIS45S/yRe9+Hug2kjxuW68G7XD m4JZAgo66i38x2TtHk2u8leuH9vzNA4c0cAfPme8tF6t7CDVoiw5gmW3o4c0cJ X-Received: by 2002:a05:600c:6211:b0:499:a760:722f with SMTP id 5b1f17b1804b1-499aa1ba0b7mr251550965e9.13.1787239536613; Thu, 20 Aug 2026 08:25:36 -0700 (PDT) Received: from runham-think ([141.5.46.228]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-499aa074740sm158441485e9.7.2026.08.20.08.25.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Aug 2026 08:25:35 -0700 (PDT) From: Syeda Mahnur Asif To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net Cc: netdev@vger.kernel.org, andrii@kernel.org, Syeda Mahnur Asif , Emil Tsalapatis Subject: [PATCH bpf v2] bpf: Fix NULL pointer dereference in bpf_sock_from_file Date: Thu, 20 Aug 2026 17:25:31 +0200 Message-ID: <20260820152532.621639-1-s.mahnur.a@gmail.com> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit bpf_sock_from_file should not dereference a NULL file pointer. KASAN detects a null-ptr-deref when eBPF tracing fentry/fexit programs are attached to points such as __mmap_region and file_map_prot_check kernel functions. This can result in a NULL file pointer flowing from context to the helper. A minimal check before dereferencing can fix this. Fixes: b60da4955f53 ("bpf: Only provide bpf_sock_from_file with CONFIG_NET") Reviewed-by: Emil Tsalapatis Signed-off-by: Syeda Mahnur Asif --- v2: - Added Reviewed-by from Emil Tsalapatis - Fixed name in Signed-off-by net/core/filter.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index 16845987b244..7c3caae4bafc 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -12182,7 +12182,10 @@ const struct bpf_func_proto bpf_skc_to_mptcp_sock_proto = { BPF_CALL_1(bpf_sock_from_file, struct file *, file) { - return (unsigned long)sock_from_file(file); + if (file) + return (unsigned long)sock_from_file(file); + + return (unsigned long)NULL; } BTF_ID_LIST(bpf_sock_from_file_btf_ids) -- 2.53.0