From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B144E6F074; Wed, 21 Feb 2024 13:36:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708522582; cv=none; b=aRwTFjj5MV0xuNcQD1JLkjtM9dWPMyJWlxxH+pmLPB9rRmjDxbS0PxvN80QY1PJ/kJ6hI+enIUSCS4hyu9L85kM+t0Pm2BoY0Dwg0vlF7Bi9ZyLIZOajPiM22kP/0RmjqMkRbR2rTOZeScUJ+WTG3QPVWEewBLLkFPmxn6/aMGg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708522582; c=relaxed/simple; bh=m6UwRotvWiBXyigTCQATqkdK45EQ+yzyoH2+VoKRE2s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tILU2hxPAOl9z/FaTuO5wlwn4ab0ozJXy/rVrxWUfa9XuOEV68X3asRsKZ9xZk9XJ7+0jQzWJXFawDk/2XGcJ/vXL5WRh9hqeW1NIWVXeHUPNcqbDYzgoNatyjzMl8BgFhDzBbzg1zAIhZp/8spVr28pMNp/rfOvV1shbil7zBQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UycPJhEY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="UycPJhEY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E597BC433C7; Wed, 21 Feb 2024 13:36:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708522582; bh=m6UwRotvWiBXyigTCQATqkdK45EQ+yzyoH2+VoKRE2s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UycPJhEYeQ2HWS/uuspgxkb5Jq9Bw60MzAgLmhN7k0SJ1UJAC6bPw/GTlcEMCbJkl JvHBbegYmx833+YRR1O/GN0tf18dIOqYiD1hlB0YJUfuD8zkmRGqQ77WRyS4jj1/au n8GszwVJOkB8w8x1kaFzZCNTfeklXOeoihZYxyas= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mingyi Zhang , Xin Liu , Changye Wu , Andrii Nakryiko , Daniel Borkmann , Sasha Levin Subject: [PATCH 5.15 199/476] libbpf: Fix NULL pointer dereference in bpf_object__collect_prog_relos Date: Wed, 21 Feb 2024 14:04:10 +0100 Message-ID: <20240221130015.278533539@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240221130007.738356493@linuxfoundation.org> References: <20240221130007.738356493@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mingyi Zhang [ Upstream commit fc3a5534e2a8855427403113cbeb54af5837bbe0 ] An issue occurred while reading an ELF file in libbpf.c during fuzzing: Program received signal SIGSEGV, Segmentation fault. 0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206 4206 in libbpf.c (gdb) bt #0 0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206 #1 0x000000000094f9d6 in bpf_object.collect_relos () at libbpf.c:6706 #2 0x000000000092bef3 in bpf_object_open () at libbpf.c:7437 #3 0x000000000092c046 in bpf_object.open_mem () at libbpf.c:7497 #4 0x0000000000924afa in LLVMFuzzerTestOneInput () at fuzz/bpf-object-fuzzer.c:16 #5 0x000000000060be11 in testblitz_engine::fuzzer::Fuzzer::run_one () #6 0x000000000087ad92 in tracing::span::Span::in_scope () #7 0x00000000006078aa in testblitz_engine::fuzzer::util::walkdir () #8 0x00000000005f3217 in testblitz_engine::entrypoint::main::{{closure}} () #9 0x00000000005f2601 in main () (gdb) scn_data was null at this code(tools/lib/bpf/src/libbpf.c): if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) { The scn_data is derived from the code above: scn = elf_sec_by_idx(obj, sec_idx); scn_data = elf_sec_data(obj, scn); relo_sec_name = elf_sec_str(obj, shdr->sh_name); sec_name = elf_sec_name(obj, scn); if (!relo_sec_name || !sec_name)// don't check whether scn_data is NULL return -EINVAL; In certain special scenarios, such as reading a malformed ELF file, it is possible that scn_data may be a null pointer Signed-off-by: Mingyi Zhang Signed-off-by: Xin Liu Signed-off-by: Changye Wu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20231221033947.154564-1-liuxin350@huawei.com Signed-off-by: Sasha Levin --- tools/lib/bpf/libbpf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index f87a15bbf53b..0c201f07d8ae 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3803,6 +3803,8 @@ bpf_object__collect_prog_relos(struct bpf_object *obj, GElf_Shdr *shdr, Elf_Data scn = elf_sec_by_idx(obj, sec_idx); scn_data = elf_sec_data(obj, scn); + if (!scn_data) + return -LIBBPF_ERRNO__FORMAT; relo_sec_name = elf_sec_str(obj, shdr->sh_name); sec_name = elf_sec_name(obj, scn); -- 2.43.0