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 D91AD1F4264; Mon, 28 Oct 2024 10:52:48 +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=1730112768; cv=none; b=CuE9zDdDvkkwGiDmUAQ36x5tTnRkKbN8ibhPEysOv2Z/TCXPDf78BXXU1A3vpOGHYy/lFWPdgeCX/4zG3bA+qpyoOsEbwBZbFPR543UqWmXGZA4JU+khco8L2eWvcJM674oVGLLyA9MGFRdiWLHb9xQQFh9qN+x9cpRsRP0HOFY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730112768; c=relaxed/simple; bh=VSoNRi8c5SQ0AzyhFBTOZSFTBGsWwJ1j/Vssn5v0a2s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Xkr3U++OkeV5+yAimWe8UD0AuqRtSdteQrEfWvYiNNEw3Y0WjMSBUXLZuynKgjYZzupX6dBGFYkaibJPOHryK24qTy2SJQO88n9Sn5U9pkVhKsCCMvHetYXHcHZ2NhgGZpwNwJAi3fKHONoy/AMHsbRz734EF0snGPh6G0uvERQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AhMra7RK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AhMra7RK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C83B3C4CEE4; Mon, 28 Oct 2024 10:52:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730112768; bh=VSoNRi8c5SQ0AzyhFBTOZSFTBGsWwJ1j/Vssn5v0a2s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AhMra7RKdG+pA9I4tLvTJQp7XquGJ4DT7HFMQyO+ey2DjOBeKqlHL9Dk2D9LVCQDa oGCrvm6IhtF0d4khe7Tf0oolaXBsHHW08ObUKFFnWQS5eY+YV9ifvwejyqlwmT3la+ Mj8dJmwX8/hIImtcuPPuF3G901aTveYUZaktqBgnz/7HUN1bkrOdVYQmAPvi7BMi7u BAFe2l68jGrOA+w+h8gOj1Jr2DO7popaJXv7zYnGzyDjq3D63k2/Wn8m37obgzM9oP 5lWC9cK6f+2F39ckfP7RKh9evAN4kTWqevu6VBKM1jMU0Cmdf4U6PfFQCOMeua+cGI hnMmo9173BEkg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hou Tao , Andrii Nakryiko , Sasha Levin , ast@kernel.org, daniel@iogearbox.net, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 15/15] bpf: Check validity of link->type in bpf_link_show_fdinfo() Date: Mon, 28 Oct 2024 06:52:11 -0400 Message-ID: <20241028105218.3559888-15-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241028105218.3559888-1-sashal@kernel.org> References: <20241028105218.3559888-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.58 Content-Transfer-Encoding: 8bit From: Hou Tao [ Upstream commit 8421d4c8762bd022cb491f2f0f7019ef51b4f0a7 ] If a newly-added link type doesn't invoke BPF_LINK_TYPE(), accessing bpf_link_type_strs[link->type] may result in an out-of-bounds access. To spot such missed invocations early in the future, checking the validity of link->type in bpf_link_show_fdinfo() and emitting a warning when such invocations are missed. Signed-off-by: Hou Tao Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20241024013558.1135167-3-houtao@huaweicloud.com Signed-off-by: Sasha Levin --- kernel/bpf/syscall.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b1933d074f051..74245c5251915 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2963,13 +2963,17 @@ static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) { const struct bpf_link *link = filp->private_data; const struct bpf_prog *prog = link->prog; + enum bpf_link_type type = link->type; char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; - seq_printf(m, - "link_type:\t%s\n" - "link_id:\t%u\n", - bpf_link_type_strs[link->type], - link->id); + if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { + seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); + } else { + WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); + seq_printf(m, "link_type:\t<%u>\n", type); + } + seq_printf(m, "link_id:\t%u\n", link->id); + if (prog) { bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); seq_printf(m, -- 2.43.0